CVE-2025-20260

Description

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.

CVSS v3.1 Score

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-122 CWE-122

Affected Products

Vendor	Product	Versions
clamav	clamav	< 1.0.9
clamav	clamav	1.2.0 — 1.4.3

References

Advisories & Patches

https://blog.clamav.net/2025/06/clamav-143-and-109-security-patch.html

Other References

https://lists.debian.org/debian-lts-announce/2025/09/msg00006.html

Frequently Asked Questions

What is CVE-2025-20260? +

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. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2025-20260? +

CVE-2025-20260 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately.

What products are affected by CVE-2025-20260? +

CVE-2025-20260 affects products from clamav, specifically: clamav. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-20260? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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