ClamAV PESpin File Format Parser integer overflow

Summaryinfo

A vulnerability classified as critical was found in ClamAV. This impacts an unknown function of the component PESpin File Format Parser. Such manipulation leads to integer overflow. This vulnerability is traded as CVE-2026-20339. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in ClamAV (version unknown). It has been rated as critical. Affected by this issue is an unknown function of the component PESpin File Format Parser. The manipulation with an unknown input leads to a integer overflow vulnerability. Using CWE to declare the problem leads to CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. Impacted is integrity, and availability. CVE summarizes:

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 as a result of memory corruption on an affected device. This vulnerability is due to improper boundary checks for content in PESpin files during scanning, which may result in an integer overflow. An attacker could exploit this vulnerability by submitting a crafted file that contains PESpin 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.

The advisory is shared for download at sec.cloudapps.cisco.com. This vulnerability is handled as CVE-2026-20339 since 10/08/2025. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-54506). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Anti-Malware Software

Name

• ClamAV

License

• free

CPE 2.3info

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CPE 2.2info

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Once again VulDB remains the best source for vulnerability data.

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