ClamAV 1.5.4 and 1.4.6 security patch versions published

Today, we are publishing the 1.5.4 and 1.4.6 security patch versions.  

The release files for the patch versions are available for download on the ClamAV downloads page, on the GitHub Release page, and through Docker Hub with both Alpine and Debian containers. The images on Docker Hub may not be immediately available on release day. Continue reading to learn what changed in each version. 

1.5.4

ClamAV 1.5.4 is a patch release with the following fixes:

• CVE-2026-20337: Fixed ZIP catalogue capacity tracking that could write beyond a heap allocation while indexing local file headers.

  This issue affects ClamAV 1.5.0 through 1.5.3. The fix is included in 1.5.4.

  Thank you to Kevin Stubbings of the GitHub Security Lab team for identifying this issue.

• CVE-2026-20345: Fixed an indexing error while converting GPT partition names that could read or write beyond a stack-allocated partition entry.

  This issue affects ClamAV 0.98.2 through 1.5.3. The fix is included in 1.4.6 and 1.5.4.

  Thank you to Atuin - Automated Vulnerability Discovery Engine, Tianchu Chen of Tencent Xuanwu Lab for identifying this issue.

• CVE-2026-20339: Fixed an integer overflow in the PESpin unpacker that could allocate an undersized buffer and then write beyond it while rebuilding a PE file.

  This issue affects ClamAV 0.90 through 1.5.3. The fix is included in 1.4.6 and 1.5.4.

  Thank you to Feng Xue and, independently, Yazdan Soltani for identifying this issue.

• CVE-2026-20338: Fixed ownership handling while merging ZIP catalogue records that could cause an invalid free while scanning a malformed archive.

  This issue affects ClamAV 1.5.0 through 1.5.3. The fix is included in 1.5.4.

  Thank you to Daggolu Rakesh and, independently, Yazdan Soltani for identifying this issue.

• CVE-2026-20346: Fixed an integer underflow in the PDF parser that could cause a crash while reading a malformed hex string.

  This issue affects ClamAV 1.4.5 and earlier, and ClamAV 1.5.0 through 1.5.3. The fix is included in 1.4.6 and 1.5.4.

  Thank you to Tristan (@TristanInSec) for identifying this issue.

• CVE-2026-20347: Fixed undefined behavior and integer overflow in the Mach-O parser that could cause a crash while scanning a malformed Mach-O file.

  This issue affects ClamAV 1.4.5 and earlier, and ClamAV 1.5.0 through 1.5.3. The fix is included in 1.4.6 and 1.5.4.

  Thank you to Tristan (@TristanInSec) for identifying this issue.

• CVE-2026-20348: Fixed XAR parser size handling that could request an excessive allocation or exceed scan limits while decompressing a malformed table of contents.

  This issue affects ClamAV 0.98.1 through 1.5.3. The fix is included in 1.4.6 and 1.5.4.

  Thank you to leduckhuong for identifying this issue.

• CVE-2025-8088: Adopted the upstream UnRAR project fix in ClamAV's bundled UnRAR library. The fix rejects path separators in NTFS alternate data stream names to prevent extraction outside ClamAV's temporary scan directory on Windows.

  This issue affects ClamAV 0.101.0 through 1.5.3. The fix is included in 1.4.6 and 1.5.4.

  Thank you to Yazdan Soltani for identifying that this issue affects ClamAV.

• Fixed thread-safety issues in the clamd STATS command that could disclose process memory or crash the daemon while scans and STATS requests run concurrently. Also fixed partial socket-write handling used for large STATS responses.

  This issue affects ClamAV 0.95 through 1.5.3. The fix is included in 1.4.6 and 1.5.4.

• FreeBSD: Restored support for safe quarantine move and remove actions while preserving protection against source-path replacement races.

  This issue affects ClamAV 1.4.5 and 1.5.3. The fix is included in 1.4.6 and 1.5.4.

• Fixed an OpenSSL library-context leak in legacy hashing helpers when a requested message digest cannot be fetched, such as when the default provider is unavailable in a FIPS-enabled environment.

  This issue affects ClamAV 1.5.0 through 1.5.3. The fix is included in 1.5.4.

• Upgraded the Rust crossbeam-epoch dependency to resolve the RUSTSEC-2026-0204 advisory.

1.4.6

ClamAV 1.4.6 is a patch release with the following fixes:

• CVE-2026-20345: Fixed an indexing error while converting GPT partition names that could read or write beyond a stack-allocated partition entry.

  This issue affects ClamAV 0.98.2 through 1.5.3. The fix is included in 1.4.6 and 1.5.4.

  Thank you to Atuin - Automated Vulnerability Discovery Engine, Tianchu Chen of Tencent Xuanwu Lab for identifying this issue.

• CVE-2026-20339: Fixed an integer overflow in the PESpin unpacker that could allocate an undersized buffer and then write beyond it while rebuilding a PE file.

  This issue affects ClamAV 0.90 through 1.5.3. The fix is included in 1.4.6 and 1.5.4.

  Thank you to Feng Xue and, independently, Yazdan Soltani for identifying this issue.

• CVE-2026-20346: Fixed an integer underflow in the PDF parser that could cause a crash while reading a malformed hex string.

  This issue affects ClamAV 1.4.5 and earlier, and ClamAV 1.5.0 through 1.5.3. The fix is included in 1.4.6 and 1.5.4.

  Thank you to Tristan (@TristanInSec) for identifying this issue.

• CVE-2026-20347: Fixed undefined behavior and integer overflow in the Mach-O parser that could cause a crash while scanning a malformed Mach-O file.

  This issue affects ClamAV 1.4.5 and earlier, and ClamAV 1.5.0 through 1.5.3. The fix is included in 1.4.6 and 1.5.4.

  Thank you to Tristan (@TristanInSec) for identifying this issue.

• CVE-2026-20348: Fixed XAR parser size handling that could request an excessive allocation or exceed scan limits while decompressing a malformed table of contents.

  This issue affects ClamAV 0.98.1 through 1.5.3. The fix is included in 1.4.6 and 1.5.4.

  Thank you to leduckhuong for identifying this issue.

• CVE-2025-8088: Adopted the upstream UnRAR project fix in ClamAV's bundled UnRAR library. The fix rejects path separators in NTFS alternate data stream names to prevent extraction outside ClamAV's temporary scan directory on Windows.

  This issue affects ClamAV 0.101.0 through 1.5.3. The fix is included in 1.4.6 and 1.5.4.

  Thank you to Yazdan Soltani for identifying that this issue affects ClamAV.

• Fixed thread-safety issues in the clamd STATS command that could disclose process memory or crash the daemon while scans and STATS requests run concurrently. Also fixed partial socket-write handling used for large STATS responses.

  This issue affects ClamAV 0.95 through 1.5.3. The fix is included in 1.4.6 and 1.5.4.

• FreeBSD: Restored support for safe quarantine move and remove actions while preserving protection against source-path replacement races.

  This issue affects ClamAV 1.4.5 and 1.5.3. The fix is included in 1.4.6 and 1.5.4.

• Upgraded the Rust crossbeam-epoch dependency to resolve the RUSTSEC-2026-0204 advisory.

ClamAV 1.5.3 and 1.4.5 security patch versions published

Today, we are publishing the 1.5.3 and 1.4.5 security patch versions.  

The release files for the patch versions are available for download on the ClamAV downloads page, on the GitHub Release page, and through Docker Hub with both Alpine and Debian containers. The images on Docker Hub may not be immediately available on release day. Continue reading to learn what changed in each version. 

1.5.3 

ClamAV 1.5.3 is a patch release with the following fixes:

• CVE-2026-20217: Fixed a bug in the PESpin unpacker cleanup path that could free pointers into the scanned file buffer and crash the scanner.

  This issue affects ClamAV 1.5.2, 1.4.4, and all prior versions as far back as 2005. The fix is included in 1.5.3 and 1.4.5.

  Thank you to Atuin - Automated Vulnerability Discovery Engine, Tianchu Chen of Tencent Xuanwu Lab for identifying this issue.

• CVE-2026-20213: Fixed an integer overflow in PE rebuild size calculations that could be reached through a malformed Aspack-packed PE file and lead to a heap buffer overflow write.

  This issue affects ClamAV 1.5.2, 1.4.4, and all prior versions as far back as 2007. The fix is included in 1.5.3 and 1.4.5.

  Thank you to Trail of Bits, in collaboration with Anthropic, for identifying this issue.

• CVE-2026-20216: Fixed an InstallShield archive extraction limit bypass that could write far more temporary data than intended and exhaust temporary storage.

  This issue affects ClamAV 1.5.2, 1.4.4, and all prior versions as far back as 2009. The fix is included in 1.5.3 and 1.4.5.

  Thank you to Mizu for identifying this issue.

• CVE-2026-20214: Fixed an FSG unpacker loop underflow that could write past the section array while scanning a malformed PE file.

  This issue affects ClamAV 1.5.2, 1.4.4, and all prior versions as far back as 2004. The fix is included in 1.5.3 and 1.4.5.

  Thank you to Trail of Bits, in collaboration with Anthropic, for identifying this issue.

• CVE-2026-20243: Fixed ALZ parser size handling bugs that could cause malformed ALZ archives to panic, abort the scanner, or skip expected scan-limit handling.

  This issue affects ClamAV 1.5.0 through 1.5.2 and 1.4.0 through 1.4.4. The fix is included in 1.5.3 and 1.4.5.

  Thank you to Yazdan Soltani for identifying this issue.

• CVE-2026-20215: Fixed a 7z parser substream count overflow that could under-allocate parser metadata arrays and write past them while reading a malformed archive.

  This issue affects ClamAV 1.5.2, 1.4.4, and all prior versions back to 2009. The fix is included in 1.5.3 and 1.4.5.

  Thank you to Trail of Bits, in collaboration with Anthropic, for identifying this issue.

• CVE-2026-20244: Fixed 32-bit DMG parser size checks that could let a short mish stripe table pass validation and crash 32-bit scanner builds.

  This issue affects 32-bit ClamAV builds from 0.98.1 through 1.5.2, including 1.4.0 through 1.4.4 and 1.5.0 through 1.5.2. It does not affect 64-bit builds. The fix is included in 1.5.3 and 1.4.5.

  Thank you to Stanley John Tobias for identifying this issue.

• Hardened clamscan, clamdscan, and clamonacc quarantine actions against time-of-check/time-of-use races that could redirect copied, moved, or removed files under unsafe quarantine directory configurations.

  Thank you to Hiroki Imai from Ricerca Security, Inc. for identifying this issue.

• Upgraded the Rust tar dependency to resolve the RUSTSEC-2026-0067 and RUSTSEC-2026-0068 advisories, and upgraded the Rust openssl dependency to resolve CVE-2026-41676.

• Raised the minimum required CMake version to 3.17 to fix Linux builds with libcurl v8.21.0 when linking static library dependencies.

• Metadata preclass scans now run before the final scan verdict.

• ClamOnAcc: Fixed errors when recursively excluded paths are children of an included path.

• ClamOnAcc: Fixed hash bucket list corruption when two watched paths collide in the same bucket.

  These fixes are courtesy of sharkautarch.

1.4.5 

ClamAV 1.4.5 is a patch release with the following fixes:

• CVE-2026-20217: Fixed a bug in the PESpin unpacker cleanup path that could free pointers into the scanned file buffer and crash the scanner.

  This issue affects ClamAV 1.5.2, 1.4.4, and all prior versions as far back as 2005. The fix is included in 1.5.3 and 1.4.5.

  Thank you to Atuin - Automated Vulnerability Discovery Engine, Tianchu Chen of Tencent Xuanwu Lab for identifying this issue.

• CVE-2026-20213: Fixed an integer overflow in PE rebuild size calculations that could be reached through a malformed Aspack-packed PE file and lead to a heap buffer overflow write.

  This issue affects ClamAV 1.5.2, 1.4.4, and all prior versions as far back as 2007. The fix is included in 1.5.3 and 1.4.5.

  Thank you to Trail of Bits, in collaboration with Anthropic, for identifying this issue.

• CVE-2026-20216: Fixed an InstallShield archive extraction limit bypass that could write far more temporary data than intended and exhaust temporary storage.

  This issue affects ClamAV 1.5.2, 1.4.4, and all prior versions as far back as 2009. The fix is included in 1.5.3 and 1.4.5.

  Thank you to Mizu for identifying this issue.

• CVE-2026-20214: Fixed an FSG unpacker loop underflow that could write past the section array while scanning a malformed PE file.

  This issue affects ClamAV 1.5.2, 1.4.4, and all prior versions as far back as 2004. The fix is included in 1.5.3 and 1.4.5.

  Thank you to Trail of Bits, in collaboration with Anthropic, for identifying this issue.

• CVE-2026-20243: Fixed ALZ parser size handling bugs that could cause malformed ALZ archives to panic, abort the scanner, or skip expected scan-limit handling.

  This issue affects ClamAV 1.5.0 through 1.5.2 and 1.4.0 through 1.4.4. The fix is included in 1.5.3 and 1.4.5.

  Thank you to Yazdan Soltani for identifying this issue.

• CVE-2026-20215: Fixed a 7z parser substream count overflow that could under-allocate parser metadata arrays and write past them while reading a malformed archive.

  This issue affects ClamAV 1.5.2, 1.4.4, and all prior versions back to 2009. The fix is included in 1.5.3 and 1.4.5.

  Thank you to Trail of Bits, in collaboration with Anthropic, for identifying this issue.

• CVE-2026-20244: Fixed 32-bit DMG parser size checks that could let a short mish stripe table pass validation and crash 32-bit scanner builds.

  This issue affects 32-bit ClamAV builds from 0.98.1 through 1.5.2, including 1.4.0 through 1.4.4 and 1.5.0 through 1.5.2. It does not affect 64-bit builds. The fix is included in 1.5.3 and 1.4.5.

  Thank you to Stanley John Tobias for identifying this issue.

• Hardened clamscan, clamdscan, and clamonacc quarantine actions against time-of-check/time-of-use races that could redirect copied, moved, or removed files under unsafe quarantine directory configurations.

  Thank you to Hiroki Imai from Ricerca Security, Inc. for identifying this issue.

• Raised the minimum required CMake version to 3.17 to fix Linux builds with libcurl v8.21.0 when linking static library dependencies.

• ClamOnAcc: Fixed errors when recursively excluded paths are children of an included path.

  This fix is courtesy of sharkautarch.

ClamAV 1.5.2 and 1.4.4 security patch versions published

Today, we are publishing the 1.5.2 and 1.4.4 security patch versions.  

The release files for the patch versions are available for download on the ClamAV downloads page, on the GitHub Release page, and through Docker Hub with both Alpine and Debian containers. The images on Docker Hub may not be immediately available on release day. Continue reading to learn what changed in each version. 

1.5.2 

ClamAV 1.5.2 is a patch release with the following fixes: 

• CVE-2026-20031: Fixed an error handling bug in the HTML file parser that may crash the program and cause a denial-of-service (DoS) condition. This issue was introduced in version 1.1.0. The fix is included in 1.5.2 and 1.4.4. 
• Fixed a possible infinite loop when scanning some JPEG files by upgrading affected ClamAV dependency, a Rust image library.  
• Unfortunately, this change requires a newer Rust compiler for ClamAV. 
  The minimum Rust version for ClamAV 1.4.3 was 1.85.1. 
  The minimum Rust version for ClamAV 1.4.4 is now 1.87.0. 
• Fixed a possible crash on Windows when scanning some files while using the LeaveTemporaryFiles and TemporaryDirectory features. 
• The CVD verification process will now ignore certificate files in the CVD certs directory when the user lacks read permissions. 
• Freshclam: Fix CLD verification bug with PrivateMirror option. 
• Upgraded the Rust bytes dependency to a newer version to resolve RUSTSEC-2026-0007 advisory. 
• Fixed a possible crash caused by invalid pointer alignment on some platforms. This fix is courtesy of Hsuan-Ming Chen at Synology PSIRT. 

1.4.4 

ClamAV 1.4.4 is a patch release with the following fixes: 

• CVE-2026-20031: Fixed an error handling bug in the HTML file parser that may crash the program and cause a DoS condition. This issue was introduced in version 1.1.0. The fix is included in 1.5.2 and 1.4.4. 
• Fixed a possible crash when scanning some TIFF files by upgrading the affected ClamAV dependency, a Rust image library. 
• Unfortunately, this change requires a newer Rust compiler for ClamAV.
  The minimum Rust version for ClamAV 1.4.3 was 1.85.1.
  The minimum Rust version for ClamAV 1.4.4 is now 1.87.0. 
• Upgraded the Rust bytes dependency to a newer version to resolve RUSTSEC-2026-0007 advisory. 
• Fixed a possible crash caused by invalid pointer alignment on some platforms. This fix is courtesy of Hsuan-Ming Chen at Synology PSIRT.