gzip integer overflow

eventfd double close

netrc and default credential leak

cURL libcurl could allow a remote attacker to bypass security restrictions, caused by a flaw when using OCSP stapling to validate server cerficate. By sending a specially crafted request, an attacker could exploit this vulnerability to establish the connection even if the certificate is revoked.

App Store. A permissions issue was addressed with additional restrictions.

Accounts. The issue was addressed with improved checks.

Accounts. The issue was addressed with improved checks.

Accounts. The issue was addressed with improved checks.

Accounts. The issue was addressed with improved checks.

Last updated 10 July 2026

Last updated 24 July 2024

cURL libcurl could allow a remote attacker to bypass security restrictions, caused by a mixed case flaw when curl is built without PSL support. By sending a specially crafted request, an attacker could exploit this vulnerability to allow a HTTP server to set "super cookies" in curl.

Accessibility. A privacy issue was addressed with improved private data redaction for log entries.

Accessibility. A privacy issue was addressed with improved private data redaction for log entries.

An authentication bypass vulnerability exists in libcurl prior to v8.0.0 where it reuses a previously established SSH connection despite the fact that an SSH option was modified which should have prevented reuse. libcurl maintains a pool of previously used connections to reuse them for subsequent transfers if the configurations match. However two SSH settings were omitted from the configuration check allowing them to match easily potentially leading to the reuse of an inappropriate connection.

A double free vulnerability exists in libcurl <8.0.0 when sharing HSTS data between separate "handles". This sharing was introduced without considerations for do this sharing across separate threads but there was no indication of this fact in the documentation. Due to missing mutexes or thread locks two threads sharing the same HSTS data could end up doing a double-free or use-after-free.

An authentication bypass vulnerability exists in libcurl <8.0.0 in the FTP connection reuse feature that can result in wrong credentials being used during subsequent transfers. Previously created connections are kept in a connection pool for reuse if they match the current setup. However certain FTP settings such as CURLOPTFTPACCOUNT CURLOPTFTPALTERNATIVETOUSER CURLOPTFTPSSLCCC and CURLOPTUSESSL were not included in the configuration match checks causing them to match too easily. This could lead to libcurl using the wrong credentials when performing a transfer potentially allowing unauthorized access to sensitive information.

A path traversal vulnerability exists in curl <8.0.0 SFTP implementation causes the tilde (~) character to be wrongly replaced when used as a prefix in the first path element in addition to its intended use as the first element to indicate a path relative to the user's home directory. Attackers can exploit this flaw to bypass filtering or execute arbitrary code by crafting a path like /~2/foo while accessing a server with a specific user.

A vulnerability in input validation exists in curl <8.0 during communication using the TELNET protocol may allow an attacker to pass on maliciously crafted user name and "telnet options" during server negotiation. The lack of proper input scrubbing allows an attacker to send content or perform option negotiation without the application's intent. This vulnerability could be exploited if an application allows user input thereby enabling attackers to execute arbitrary code on the system.

An authentication bypass vulnerability exists libcurl <8.0.0 in the connection reuse feature which can reuse previously established connections with incorrect user permissions due to a failure to check for changes in the CURLOPTGSSAPIDELEGATION option. This vulnerability affects krb5/kerberos/negotiate/GSSAPI transfers and could potentially result in unauthorized access to sensitive information. The safest option is to not reuse connections if the CURLOPTGSSAPIDELEGATION option has been changed.

A cleartext transmission of sensitive information vulnerability exists in curl <v7.88.0 that could cause HSTS functionality to behave incorrectly when multiple URLs are requested in parallel. Using its HSTS support, curl can be instructed to use HTTPS instead of using an insecure clear-text HTTP step even when HTTP is provided in the URL. This HSTS mechanism would however surprisingly fail when multiple transfers are done in parallel as the HSTS cache file gets overwritten by the most recentlycompleted transfer. A later HTTP-only transfer to the earlier host name would then not get upgraded properly to HSTS.

A cleartext transmission of sensitive information vulnerability exists in curl <v7.88.0 that could cause HSTS functionality fail when multiple URLs are requested serially. Using its HSTS support, curl can be instructed to use HTTPS instead of usingan insecure clear-text HTTP step even when HTTP is provided in the URL. ThisHSTS mechanism would however surprisingly be ignored by subsequent transferswhen done on the same command line because the state would not be properlycarried on.

An allocation of resources without limits or throttling vulnerability exists in curl <v7.88.0 based on the "chained" HTTP compression algorithms, meaning that a server response can be compressed multiple times and potentially with differentalgorithms. The number of acceptable "links" in this "decompression chain" wascapped, but the cap was implemented on a per-header basis allowing a maliciousserver to insert a virtually unlimited number of compression steps simply byusing many headers. The use of such a decompression chain could result in a "malloc bomb", making curl end up spending enormous amounts of allocated heap memory, or trying to and returning out of memory errors.

A vulnerability exists in curl <7.87.0 HSTS check that could be bypassed to trick it to keep using HTTP. Using its HSTS support, curl can be instructed to use HTTPS instead of using an insecure clear-text HTTP step even when HTTP is provided in the URL. However, the HSTS mechanism could be bypassed if the host name in the given URL first uses IDN characters that get replaced to ASCII counterparts as part of the IDN conversion. Like using the character UTF-8 U+3002 (IDEOGRAPHIC FULL STOP) instead of the common ASCII full stop (U+002E) .. Then in a subsequent request, it does not detect the HSTS state and makes a clear text transfer. Because it would store the info IDN encoded but look for it IDN decoded.

A use after free vulnerability exists in curl <7.87.0. Curl can be asked to tunnel virtually all protocols it supports through an HTTP proxy. HTTP proxies can (and often do) deny such tunnel operations. When getting denied to tunnel the specific protocols SMB or TELNET, curl would use a heap-allocated struct after it had been freed, in its transfer shutdown code path.

A vulnerability was found in curl. The issue occurs if curl is told to use an HTTP proxy for a transfer with a non-HTTP(S) URL. It sets up the connection to the remote server by issuing a CONNECT request to the proxy and then tunnels the rest of the protocol through. An HTTP proxy might refuse this request (HTTP proxies often only allow outgoing connections to specific port numbers, like 443 for HTTPS) and instead return a non-200 response code to the client. Due to flaws in the error/cleanup handling, this could trigger a double-free issue in curl if using one of the following schemes in the URL for the transfer: dict, gopher, gophers, ldap, ldaps, rtmp, rtmps, telnet.

A vulnerability was found in curl. The issue occurs because curl's HSTS check can be bypassed to trick it to keep using HTTP. Using its HSTS support, it can instruct curl to use HTTPS directly instead of using an insecure clear-text HTTP step even when HTTP is provided in the URL. This mechanism can be bypassed if the hostname in the given URL uses IDN characters that get replaced with ASCII counterparts as part of the IDN conversion. Like using the character UTF-8 U+3002 (IDEOGRAPHIC FULL STOP) instead of the common ASCII full stop (U+002E) ..

Accelerate. An out-of-bounds read was addressed with improved bounds checking.

When doing SSH-based transfers using either SCP or SFTP, and asked to do public key authentication, curl would wrongly still ask and authenticate using a locally running SSH agent.

A vulnerability found in curl. This security flaw happens when curl is used to retrieve and parse cookies from an HTTP(S) server, where it accepts cookies using control codes (byte values below 32), and also when cookies that contain such control codes are later sent back to an HTTP(S) server, possibly causing the server to return a 400 response. This issue effectively allows a "sister site" to deny service to siblings and cause a denial of service attack.