A vulnerability in the XAR file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition or possibly other expanded impacts as a result of memory corruption on an affected device. This vulnerability is due to improper boundary checks for content in XAR files during scanning. An attacker could exploit this vulnerability by submitting a crafted file that contains XAR content to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software.

A vulnerability in the GPT file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition or possibly other expanded impacts as a result of memory corruption on an affected device. This vulnerability is due to improper handling of an endian conversion operation, which may result in an out-of-bounds buffer write. An attacker could exploit this vulnerability by submitting a crafted GPT file to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software.

A vulnerability in the Mach-O file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition or possibly other expanded impacts as a result of memory corruption on an affected device. This vulnerability is due to improper boundary checks for content in Mach-O files during scanning, which may result in an out-of-bounds buffer read. An attacker could exploit this vulnerability by submitting a crafted Mach-O file to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software.

A vulnerability in the zip archive parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device. This vulnerability is due to improper memory handling when processing content in zip files during scanning. An attacker could exploit this vulnerability by submitting a crafted zip file for scanning. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate as a result of a memory double-free, resulting in a DoS condition on the affected software.

A vulnerability in the zip archive parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device. This vulnerability is due to improper boundary checks for content in zip files during scanning, which may result in an out-of-bounds write condition. An attacker could exploit this vulnerability by submitting a crafted zip file for scanning. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software.

A vulnerability in the ALZ file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device.

A vulnerability in the DMG file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device.

A vulnerability in the 7z file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device.

A vulnerability in the PESpin file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device.

A vulnerability in the InstallShield file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device.

A vulnerability in the PE file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device.

A vulnerability in the FSG file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device.

On July 1, 2026, the Cisco Product Security Incident Response Team (PSIRT) published the following advisories:Cisco Security AdvisoryCVE-IDSecurity Impact RatingCVSS Base ScoreCisco Catalyst Center Arbitrary File Read VulnerabilityCVE-2026-20191High7.5ClamAV Vulnerabilities Affecting Cisco Products: July 2026CVE-2026-20216CVE-2026-20213CVE-2026-20214CVE-2026-20215CVE-2026-20217CVE-2026-20243CVE-2026-20244High7.5To fully remediate the vulnerabilities that were disclosed on July 1, 2026, Cisco strongly recommends that customers upgrade to the fixed software that is indicated in the advisories.For more information about changes in Cisco PSIRT vulnerability disclosure, see Strengthening the Foundation: A Predictable, Customer-Focused Response to AI-Accelerated Vulnerability Discovery.

ClamAV versions prior to 0.103.0-rc contain a vulnerability in function name processing through the ClamBC bytecode interpreter that allows attackers to manipulate bytecode function names. Attackers can exploit the weak input validation in function name encoding to potentially execute malicious bytecode or cause unexpected behavior in the ClamAV engine.

A vulnerability in the PDF scanning processes of ClamAV could allow an unauthenticated, remote attacker to cause a buffer overflow condition, cause a denial of service (DoS) condition, or execute arbitrary code on an affected device. This vulnerability exists because memory buffers are allocated incorrectly when PDF files are processed. An attacker could exploit this vulnerability by submitting a crafted PDF file to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to trigger a buffer overflow, likely resulting in the termination of the ClamAV scanning process and a DoS condition on the affected software. Although unproven, there is also a possibility that an attacker could leverage the buffer overflow to execute arbitrary code with the privileges of the ClamAV process.

A vulnerability in the VirusEvent feature of ClamAV could allow a local attacker to inject arbitrary commands with the privileges of the application service account.The vulnerability is due to unsafe handling of file names. A local attacker could exploit this vulnerability by supplying a file name containing command-line sequences. When processed on a system using configuration options for the VirusEvent feature, the attacker could cause the application to execute arbitrary commands. ClamAV has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

A vulnerability in the EGG archive parsing module in Clam AntiVirus (ClamAV) Software versions 0.102.0 - 0.102.3 could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to a null pointer dereference. An attacker could exploit this vulnerability by sending a crafted EGG file to an affected device. An exploit could allow the attacker to cause the ClamAV scanning process crash, resulting in a denial of service condition.

A vulnerability in the Data-Loss-Prevention (DLP) module in Clam AntiVirus (ClamAV) Software versions 0.102.1 and 0.102.0 could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to an out-of-bounds read affecting users that have enabled the optional DLP feature. An attacker could exploit this vulnerability by sending a crafted email file to an affected device. An exploit could allow the attacker to cause the ClamAV scanning process crash, resulting in a denial of service condition.

A vulnerability in the email parsing module Clam AntiVirus (ClamAV) Software versions 0.102.0, 0.101.4 and prior could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to inefficient MIME parsing routines that result in extremely long scan times of specially formatted email files. An attacker could exploit this vulnerability by sending a crafted email file to an affected device. An exploit could allow the attacker to cause the ClamAV scanning process to scan the crafted email file indefinitely, resulting in a denial of service condition.

ClamAV before 0.97.7: dbgprinthex possible information leak

ClamAV before 0.97.7 has buffer overflow in the libclamav component

ClamAV before 0.97.7 has WWPack corrupt heap memory

clamav 0.91.2 suffers from a floating point exception when using ScanOLE2.

There is a possible heap overflow in libclamav/fsg.c before 0.100.0.

A vulnerability in ClamAV versions prior to 0.100.2 could allow an attacker to cause a denial of service (DoS) condition. The vulnerability is due to an error related to the MEW unpacker within the "unmew11()" function (libclamav/mew.c), which can be exploited to trigger an invalid read memory access via a specially crafted EXE file.

ClamAV before 0.100.1 lacks a PDF object length check, resulting in an unreasonably long time to parse a relatively small file.

ClamAV before 0.100.1 has an HWP integer overflow with a resultant infinite loop via a crafted Hangul Word Processor file. This is in parsehwp3paragraph() in libclamav/hwp.c.

clamscan in ClamAV before 0.99.4 contains a vulnerability 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 input validation checking mechanisms when handling Portable Document Format (.pdf) files sent to an affected device. An unauthenticated, remote attacker could exploit this vulnerability by sending a crafted .pdf file to an affected device. This action could cause an out-of-bounds read when ClamAV scans the malicious file, allowing the attacker to cause a DoS condition. This concerns pdfparsearray and pdfparsestring in libclamav/pdfng.c. Cisco Bug IDs: CSCvh91380, CSCvh91400.

ClamAV version version 0.99.3 contains a Out of bounds heap memory read vulnerability in XAR parser, function xarhashcheck() that can result in Leaking of memory, may help in developing exploit chains.. This attack appear to be exploitable via The victim must scan a crafted XAR file. This vulnerability appears to have been fixed in after commit d96a6b8bcc7439fa7e3876207aa0a8e79c8451b6.

ClamAV AntiVirus software versions 0.99.2 and prior contain a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition or potentially execute arbitrary code on an affected device. The vulnerability is due to improper input validation checking mechanisms in the message parsing function on an affected system. An unauthenticated, remote attacker could exploit this vulnerability by sending a crafted email to the affected device. This action could cause a messageAddArgument (in message.c) buffer overflow condition when ClamAV scans the malicious email, allowing the attacker to potentially cause a DoS condition or execute arbitrary code on an affected device.