Vulnerability in pillow (CVE-2026-42309)
Summary
Vulnerability in pillow (CVE-2026-42309). Risk of unauthorized operations or information disclosure. Exploitable via ImagePath.Path. Mitigation: upgrade to 12.2.0 or later.
Original description
The description as published by the source.
Pillow is a Python imaging library. From version 11.2.1 to before version 12.2.0, passing nested lists as coordinates to APIs that accept coordinates such as ImagePath.Path, ImageDraw.ImageDraw.polygon and ImageDraw.ImageDraw.line could cause a heap buffer overflow, as nested lists were recursively unpacked beyond the allocated buffer. Coordinate lists are now validated to contain exactly two numeric coordinates. This issue has been patched in version 12.2.0.
Source: NIST National Vulnerability Database 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-2026-42309 has been found in pillow.
Attackers can target a specific entry point like ImagePath.Path over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.5/10.
What to do: upgrade pillow to 12.2.0 or later.
If unsure, ask your IT team or search "pillow CVE-2026-42309" on the vendor's site.
CVE-2026-42309 (pillow) — CWE-122 / CVSS v3 5.5
Attack vector: local / no user interaction
Attack surface: ImagePath.Path / ImageDraw.ImageDraw.polygon / ImageDraw.ImageDraw.line
Patched: 12.2.0 — apply immediately
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-122) exists in pillow. Attackers reach the vulnerable code path via ImagePath.Path.
Check the vendor advisory for the affected versions of pillow. Attack surface: ImagePath.Path / ImageDraw.ImageDraw.polygon / ImageDraw.ImageDraw.line.
Severity: Medium (CVSS 5.5/10). Risk of unauthorized operations or information disclosure.
Update to 12.2.0.
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 'pillow' . 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
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1Identify exposure identify
grep -r 'pillow' . | 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
pillowを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade pillow to 12.2.0ステージング環境で 12.2.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-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
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-42309 pillow Fixed in: 12.2.0-1
- Ubuntu UBUNTU-CVE-2026-42309 pillow
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com
- web github.com