Multiple Cisco products are affected by a vulnerability in the Snort detection engine that could allow an unauthenticated, remote attacker to bypass the configured file policies on an affected system. The vulnerability is due to errors in how the Snort detection engine handles specific HTTP responses. An attacker could exploit this vulnerability by sending crafted HTTP packets that would flow through an affected system. A successful exploit could allow the attacker to bypass the configured file policies and deliver a malicious payload to the protected network.

Multiple Cisco products are affected by a vulnerability with TCP Fast Open (TFO) when used in conjunction with the Snort detection engine that could allow an unauthenticated, remote attacker to bypass a configured file policy for HTTP. The vulnerability is due to incorrect detection of the HTTP payload if it is contained at least partially within the TFO connection handshake. An attacker could exploit this vulnerability by sending crafted TFO packets with an HTTP payload through an affected device. A successful exploit could allow the attacker to bypass configured file policy for HTTP packets and deliver a malicious payload.

Multiple Cisco products are affected by a vulnerability in the Snort detection engine that could allow an unauthenticated, remote attacker to bypass a configured file policy for HTTP. The vulnerability is due to incorrect handling of an HTTP range header. An attacker could exploit this vulnerability by sending crafted HTTP packets through an affected device. A successful exploit could allow the attacker to bypass configured file policy for HTTP packets and deliver a malicious payload.

Multiple Cisco products are affected by a vulnerability in the Snort application detection engine that could allow an unauthenticated, remote attacker to bypass the configured policies on an affected system. The vulnerability is due to a flaw in the detection algorithm. An attacker could exploit this vulnerability by sending crafted packets that would flow through an affected system. A successful exploit could allow the attacker to bypass the configured policies and deliver a malicious payload to the protected network.

Multiple Cisco products are affected by a vulnerability in the way the Snort detection engine processes ICMP traffic that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper memory resource management while the Snort detection engine is processing ICMP packets. An attacker could exploit this vulnerability by sending a series of ICMP packets through an affected device. A successful exploit could allow the attacker to exhaust resources on the affected device, causing the device to reload.

A vulnerability in the stream reassembly component of Cisco Firepower Threat Defense Software, Cisco FirePOWER Services Software for ASA, and Cisco Firepower Management Center Software could allow an unauthenticated, remote attacker to bypass filtering protections. The vulnerability is due to improper reassembly of traffic streams. An attacker could exploit this vulnerability by sending crafted streams through an affected device. An exploit could allow the attacker to bypass filtering and deliver malicious requests to protected systems that would otherwise be blocked.

A vulnerability in the normalization functionality of Cisco Firepower Threat Defense Software, Cisco FirePOWER Services Software for ASA, and Cisco Firepower Management Center Software could allow an unauthenticated, remote attacker to bypass filtering protections. The vulnerability is due to insufficient normalization of a text-based payload. An attacker could exploit this vulnerability by sending traffic that contains specifically obfuscated payloads through an affected device. An exploit could allow the attacker to bypass filtering and deliver malicious payloads to protected systems that would otherwise be blocked.

A vulnerability in the protocol detection component of Cisco Firepower Threat Defense Software, Cisco FirePOWER Services Software for ASA, and Cisco Firepower Management Center Software could allow an unauthenticated, remote attacker to bypass filtering protections. The vulnerability is due to improper detection of the initial use of a protocol on a nonstandard port. An attacker could exploit this vulnerability by sending traffic on a nonstandard port for the protocol in use through an affected device. An exploit could allow the attacker to bypass filtering and deliver malicious requests to protected systems that would otherwise be blocked. Once the initial protocol flow on the nonstandard port is detected, future flows on the nonstandard port will be successfully detected and handled as configured by the applied policy.

A vulnerability in the sfmgr daemon of Cisco Firepower Management Center (FMC) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to perform directory traversal and access directories outside the restricted path. The vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by using a relative path in specific sfmgr commands. An exploit could allow the attacker to read or write arbitrary files on an sftunnel-connected peer device.

A vulnerability in the sftunnel functionality of Cisco Firepower Management Center (FMC) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to obtain the device registration hash. The vulnerability is due to insufficient sftunnel negotiation protection during initial device registration. An attacker in a man-in-the-middle position could exploit this vulnerability by intercepting a specific flow of the sftunnel communication between an FMC device and an FTD device. A successful exploit could allow the attacker to decrypt and modify the sftunnel communication between FMC and FTD devices, allowing the attacker to modify configuration data sent from an FMC device to an FTD device or alert data sent from an FTD device to an FMC device.

A vulnerability in the Image Signature Verification feature of Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker with administrator-level credentials to install a malicious software patch on an affected device. The vulnerability is due to improper verification of digital signatures for patch images. An attacker could exploit this vulnerability by crafting an unsigned software patch to bypass signature checks and loading it on an affected device. A successful exploit could allow the attacker to boot a malicious software patch image.

A vulnerability in the configuration of the Pluggable Authentication Module (PAM) used in Cisco Firepower Threat Defense (FTD) Software, Cisco Firepower Management Center (FMC) Software, and Cisco FXOS Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to improper resource management in the context of user session management. An attacker could exploit this vulnerability by connecting to an affected system and performing many simultaneous successful Secure Shell (SSH) logins. A successful exploit could allow the attacker to exhaust system resources and cause the device to reload, resulting in a DoS condition. To exploit this vulnerability, the attacker needs valid user credentials on the system.

A vulnerability in the Secure Sockets Layer (SSL)/Transport Layer Security (TLS) protocol inspection engine of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass the configured file policies on an affected system. The vulnerability is due to errors when handling specific SSL/TLS messages. An attacker could exploit this vulnerability by sending crafted HTTP packets that would flow through an affected system. A successful exploit could allow the attacker to bypass the configured file policies and deliver a malicious payload to the protected network.

A vulnerability in the password change feature of Cisco Firepower Management Center (FMC) software could allow an unauthenticated, remote attacker to determine valid user names on an affected device. This vulnerability is due to improper authentication of password update responses. An attacker could exploit this vulnerability by forcing a password reset on an affected device. A successful exploit could allow the attacker to determine valid user names in the unauthenticated response to a forced password reset.

Multiple Cisco products are affected by a vulnerability in Snort rules that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.The vulnerability is due to improper handling of the Block with Reset or Interactive Block with Reset actions if a rule is configured without proper constraints. An attacker could exploit this vulnerability by sending a crafted IP packet to the affected device. A successful exploit could allow the attacker to cause through traffic to be dropped. Note: Only products with Snort3 configured and either a rule with Block with Reset or Interactive Block with Reset actions configured are vulnerable. Products configured with Snort2 are not vulnerable.

A vulnerability in the HTTP traffic filtering component of Cisco Firepower Threat Defense Software, Cisco FirePOWER Services Software for ASA, and Cisco Firepower Management Center Software could allow an unauthenticated, remote attacker to bypass filtering protections. The vulnerability is due to improper handling of HTTP requests, including those communicated over a secure HTTPS connection, that contain maliciously crafted headers. An attacker could exploit this vulnerability by sending malicious requests to an affected device. An exploit could allow the attacker to bypass filtering and deliver malicious requests to protected systems, allowing attackers to deliver malicious content that would otherwise be blocked.

A vulnerability in the multi-instance feature of Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, local attacker to escape the container for their Cisco FTD instance and execute commands with root privileges in the host namespace. The attacker must have valid credentials on the device.The vulnerability exists because a configuration file that is used at container startup has insufficient protections. An attacker could exploit this vulnerability by modifying a specific container configuration file on the underlying file system. A successful exploit could allow the attacker to execute commands with root privileges within the host namespace. This could allow the attacker to impact other running Cisco FTD instances or the host Cisco FXOS device.

Multiple vulnerabilities in the payload inspection for Ethernet Industrial Protocol (ENIP) traffic for Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured rules for ENIP traffic. These vulnerabilities are due to incomplete processing during deep packet inspection for ENIP packets. An attacker could exploit these vulnerabilities by sending a crafted ENIP packet to the targeted interface. A successful exploit could allow the attacker to bypass configured access control and intrusion policies that should be activated for the ENIP packet.

Multiple vulnerabilities in the Server Message Block (SMB) Protocol preprocessor detection engine for Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, adjacent or remote attacker to cause a denial of service (DoS) condition. For more information about these vulnerabilities, see the Details section of this advisory.

A vulnerability in the CLI of Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, local attacker to perform a command injection attack. The vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by injecting commands into arguments for a specific command. A successful exploit could allow the attacker to execute commands with root privileges.

A vulnerability in the processing of SSH connections of Cisco Firepower Management Center (FMC) and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper error handling when an SSH session fails to be established. An attacker could exploit this vulnerability by sending a high rate of crafted SSH connections to the instance. A successful exploit could allow the attacker to cause resource exhaustion, resulting in a reboot on the affected device.

A vulnerability in the implementation of the Lua interpreter integrated in Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to execute arbitrary code with root privileges on the underlying Linux operating system of an affected device. The vulnerability is due to insufficient restrictions on the allowed Lua function calls within the context of user-supplied Lua scripts. A successful exploit could allow the attacker to trigger a heap overflow condition and execute arbitrary code with root privileges on the underlying Linux operating system of an affected device.

A vulnerability in the detection engine reassembly of Secure Sockets Layer (SSL) packets for Cisco Firepower System Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition because the Snort process consumes a high level of CPU resources. Affected Products: This vulnerability affects Cisco Firepower System Software running software releases 6.0.0, 6.1.0, 6.2.0, or 6.2.1 when the device is configured with an SSL policy that has at least one rule specifying traffic decryption. More Information: CSCvc58563. Known Affected Releases: 6.0.0 6.1.0 6.2.0 6.2.1.

A vulnerability in the web framework of Cisco Firepower Management Center could allow an authenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the web interface. More Information: CSCvc72741. Known Affected Releases: 6.2.1.

A vulnerability in Cisco Firepower System Software could allow an unauthenticated, remote attacker to maliciously bypass the appliance's ability to block certain web content, aka a URL Bypass. More Information: CSCvb93980. Known Affected Releases: 5.3.0 5.4.0 6.0.0 6.0.1 6.1.0.

A vulnerability in the Policy deployment module of the Cisco Firepower Management Center (FMC) could allow an unauthenticated, remote attacker to prevent deployment of a complete and accurate rule base. More Information: CSCvb95281. Known Affected Releases: 6.1.0 6.2.0. Known Fixed Releases: 6.1.0.1 6.2.0.

I'm prob a little late but yall see this from last week!? Cisco FMC—CISA announced a big vulnerability last week. They added CVE-2026-20131 to the KEV list with a "fix it now" deadline that expired yesterday.

This one is a 10.0 severity auth bypass. If an attacker can reach your management interface, they pretty much own the box. We had a minor heart attack realizing a few of our legacy consoles weren't showing up in our central dashboard, so we had to go in and audit them manually. Most of our older boxes were sitting on 7.2.x, which is a wide-open door for this.

If you all haven’t checked your versions yet, you’re basically flying blind on a max-severity flaw. I’m tracking the technical specifics and version requirements here: https://www.cveintel.tech/cve/CVE-2026-20131.

Is everyone else actually patched, or is this going to be a long Monday for some of yall?

EDIT: A few people asked for the specific build versions and the ITIL notes I used for our CAB meeting. I’ve put the full technical brief here: https://www.cveintel.tech/cve/CVE-2026-20131

A vulnerability in the web-based management interface of Cisco Firepower Management Center could allow an unauthenticated, remote attacker to conduct a cross-site request forgery (CSRF) attack and perform arbitrary actions on an affected device. The vulnerability is due to insufficient CSRF protections for the web-based management interface of the affected device. An attacker could exploit this vulnerability by persuading a user of the interface to follow a malicious link. A successful exploit could allow the attacker to perform arbitrary actions on the targeted device via a web browser and with the privileges of the user. Cisco Bug IDs: CSCvb19750.

A vulnerability in SSL traffic decryption for Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause depletion of system memory, aka a Firepower Detection Engine SSL Decryption Memory Consumption Denial of Service vulnerability. If this memory leak persists over time, a denial of service (DoS) condition could develop because traffic can cease to be forwarded through the device. The vulnerability is due to an error in how the Firepower Detection Snort Engine handles SSL traffic decryption and notifications to and from the Adaptive Security Appliance (ASA) handler. An attacker could exploit this vulnerability by sending a steady stream of malicious Secure Sockets Layer (SSL) traffic through the device. An exploit could allow the attacker to cause a DoS condition when the device runs low on system memory. This vulnerability affects Cisco Firepower Threat Defense (FTD) Software Releases 6.0.1 and later, running on any of the following Cisco products: Adaptive Security Appliance (ASA) 5500-X Series Next-Generation Firewalls, Firepower 2100 Series Security Appliances, Firepower 4100 Series Security Appliances, Firepower 9300 Series Security Appliances. Cisco Bug IDs: CSCve02069.

A vulnerability in the detection engine parsing of IPv6 packets for Cisco Firepower System Software could allow an unauthenticated, remote attacker to cause high CPU utilization or to cause a denial of service (DoS) condition because the Snort process restarts unexpectedly. The vulnerability is due to improper input validation of the fields in the IPv6 extension header packet. An attacker could exploit this vulnerability by sending a malicious IPv6 packet to the detection engine on the targeted device. An exploit could allow the attacker to cause a DoS condition if the Snort process restarts and traffic inspection is bypassed or traffic is dropped. This vulnerability is specific to IPv6 traffic only. This vulnerability affects Cisco Firepower System Software Releases 6.0 and later when the software has one or more file action policies configured and is running on any of the following Cisco products: 3000 Series Industrial Security Appliances (ISR), Adaptive Security Appliance (ASA) 5500-X Series with FirePOWER Services, Adaptive Security Appliance (ASA) 5500-X Series Next-Generation Firewalls, Advanced Malware Protection (AMP) for Networks, 7000 Series Appliances, Advanced Malware Protection (AMP) for Networks, 8000 Series Appliances, FirePOWER 7000 Series Appliances, FirePOWER 8000 Series Appliances, Firepower Threat Defense for Integrated Services Routers (ISRs), Firepower 2100 Series Security Appliances, Firepower 4100 Series Security Appliances, Firepower 9300 Series Security Appliances, Virtual Next-Generation Intrusion Prevention System (NGIPSv) for VMware. Cisco Bug IDs: CSCvd34776.