Vulnerability in PDFio (CVE-2026-77220)
Summary
Vulnerability in PDFio (CVE-2026-77220). Data can be tampered with by attackers.
Original description
The description as published by the source.
PDFio before 1.6.5 contains a dangling pointer vulnerability in the dictionary string-formatting function that stores a pointer to a stack-local buffer in the document dictionary without copying the string value. In multi-threaded or pooled-request environments, attackers or concurrent users can trigger stack memory reuse across requests, causing cross-tenant document content corruption by silently overwriting one caller's dictionary string values with another caller's data.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
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 CVE-2026-77220 has been found in PDFio.
Data can be tampered with by attackers. CVSS score: 6.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "PDFio CVE-2026-77220" on the vendor's site.
CVE-2026-77220 (PDFio) — CWE-825 / CVSS v3 6.5
Attack vector: remote (network-reachable) / 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.
A vulnerability (CWE-825) exists in PDFio.
Check the vendor advisory for the affected versions of PDFio.
Severity: Medium (CVSS 6.5/10). Data can be tampered with by attackers.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'PDFio' . 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
-
1Identify exposure identify
grep -r 'PDFio' . | 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
PDFioを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-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。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-77220 ippsample
- Ubuntu UBUNTU-CVE-2026-77220 ippsample
References
- web nvd.nist.gov
- web disclosure@vulncheck.com
- web disclosure@vulncheck.com
- web disclosure@vulncheck.com
- web github.com