Vulnerability in php-dompdf (UBUNTU-CVE-2026-59941)

Summary

Vulnerability in php-dompdf (UBUNTU-CVE-2026-59941). Risk of unauthorized operations or information disclosure.

Original description

The description as published by the source.

Dompdf is an HTML to PDF converter for PHP. Versions 3.15 and prior accept a BMP image and generates a PDF-compatible PNG based only on its declared header dimensions and never bounds width × height before the image is converted through GD. A 58-byte BMP whose header declares e.g. 6000×6000 is accepted and later drives imagecreatetruecolor($width, $height) (and PHP's native BMP decoder) to allocate the full pixel canvas. A payload can fit in a single HTTP request: the BMP can be inlined as a data:image/bmp;base64,… URI inside attacker-controlled HTML, so no upload, no remote fetch, and no chroot-reachable file is required. I measured a 169-byte request driving a dompdf render to ~412 MB peak RSS and ~4.8 s of CPU/wall time, versus ~34 MB for an identically-sized benign request — roughly a 12× memory amplification per request, repeatable and unauthenticated. This issue has been fixed in version 3.16.

Source: OSV.dev (Open Source Vulnerabilities) OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as UBUNTU-CVE-2026-59941 has been found in php-dompdf.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "php-dompdf UBUNTU-CVE-2026-59941" on the vendor's site.

UBUNTU-CVE-2026-59941 (php-dompdf)
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (unclassified) exists in php-dompdf.

📍 Affected scope

Check the vendor advisory for the affected versions of php-dompdf.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to the patched release per vendor advisory.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'php-dompdf' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'php-dompdf' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で php-dompdf を grep し、稼働しているサービス・バージョンを把握する。
2
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

Ubuntu:Pro:16.04:LTS php-dompdf

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Ubuntu:Pro:18.04:LTS php-dompdf

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Ubuntu:20.04:LTS php-dompdf

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Ubuntu:22.04:LTS php-dompdf

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

References

report ubuntu.com
report cve.org
report github.com
report github.com
report github.com