CVE-2025-20260
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceClamAV contains a buffer overflow vulnerability in its PDF scanning functionality due to incorrect memory buffer allocation during PDF parsing. An unauthenticated remote attacker can exploit this by submitting a crafted PDF file to be scanned, causing a buffer overflow that can crash the scanning process (DoS) or potentially execute arbitrary code with ClamAV process privileges.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 1.0.9>= 1.2.0, < 1.4.3CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed ClamAV versionRun `clamscan --version` or `clamd --version` to obtain the exact version number. Alternatively, query the package manager (e.g., `dpkg -l | grep clamav`, `rpm -q clamav`, or `brew list clamav` on macOS).Affected if The version is less than 1.0.9, OR greater than or equal to 1.2.0 but less than 1.4.3 (for example: 1.0.8, 1.2.0, 1.3.1, 1.4.2 are all vulnerable). Versions 1.0.9 through 1.2.0 (exclusive of 1.2.0) and 1.4.3 or higher are not affected.
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Confirm ClamAV scanning is activeVerify the clamd service is running (`systemctl status clamd` or `ps aux | grep clamd`) or that clamscan/clamdscan commands are in use. Check configuration files in /etc/clamd/ or /etc/clamav/ for active scanning directives.Affected if ClamAV is actively scanning files (either via clamd daemon or on-demand clamscan), as the vulnerability triggers during the scanning process.
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Identify if PDF files are processed by ClamAVReview scanning workflows or email gateway configurations to see if PDF attachments are routed to ClamAV for virus scanning. Check ifclamd.conf or clamscan commands include PDF-heavy paths like mail queues, upload directories, or file shares.Affected if PDF files from untrusted or unknown sources are being scanned by ClamAV (the vulnerability lies in the PDF parsing code within libclamav, which processes PDFs automatically when they are submitted for scanning).
You are affected if your installed ClamAV version falls within the vulnerable ranges (<1.0.9 or >=1.2.0 to <1.4.3) AND you use ClamAV to scan PDF files from potentially untrusted sources.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped1.0.91.4.3
Update ClamAV to the vendor-patched version. As a temporary workaround, avoid scanning untrusted or unknown PDF files with ClamAV until the patch can be applied.
ClamAV 1.0.9 (for 1.0.x branch) or ClamAV 1.4.3 (for 1.2.x-1.4.x branch)
- 1. Identify the current installed version of ClamAV using 'clamconf --version' or 'clamscan --version'
- 2. Determine which version branch is currently in use (1.0.x or 1.2.x-1.4.x)
- 3. For ClamAV 1.0.x branch: upgrade to version 1.0.9 or later
- 4. For ClamAV 1.2.x-1.4.x branch: upgrade to version 1.4.3 or later
- 5. Use the appropriate package manager or source to upgrade (e.g., 'apt-get update && apt-get install clamav' for Debian/Ubuntu, or 'yum update clamav' for RHEL/CentOS)
- 6. After upgrade, verify the new version is installed correctly
- 7. Test the updated ClamAV with a sample PDF scan to ensure functionality
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-20260 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-20260 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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