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.