Out-of-Bounds Write in zlib (CVE-2026-22184)
Summary
Out-of-bounds write in zlib (CVE-2026-22184). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
zlib versions up to and including 1.3.1.2 contain a global buffer overflow in the untgz utility. The TGZfname() function copies an attacker-supplied archive name from argv[] into a fixed-size 1024-byte static global buffer using an unbounded strcpy() call without length validation. Supplying an archive name longer than 1024 bytes results in an out-of-bounds write that can lead to memory corruption, denial of service, and potentially code execution depending on compiler, build flags, architecture, and memory layout. The overflow occurs prior to any archive parsing or validation.
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-2026-22184 has been found in zlib.
Successful exploitation can lead to full system takeover. CVSS score: 7.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "zlib CVE-2026-22184" on the vendor's site.
CVE-2026-22184 (zlib) — CWE-787 / CVSS v3 7.8
Attack vector: local / 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.
Out-of-bounds write (CWE-787) exists in zlib.
Check the vendor advisory for the affected versions of zlib.
Severity: High (CVSS 7.8/10). Successful exploitation can lead to full system takeover.
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 'zlib' . 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 'zlib' . | 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
zlib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
- Alpine Linux ALPINE-CVE-2026-22184 zlib Fixed in: 1.3.2-r0
- Debian DEBIAN-CVE-2026-22184 zlib Fixed in: 1:1.2.6.dfsg-1
- Ubuntu UBUNTU-CVE-2026-22184 zsync
References
- advisory disclosure@vulncheck.com
- advisory disclosure@vulncheck.com
- issue github.com
- web nvd.nist.gov
- web disclosure@vulncheck.com
- web zlib.net
- web access.redhat.com
- web bugzilla.redhat.com
- web security.access.redhat.com
- web github.com
- web disclosure@vulncheck.com
- web cert-portal.siemens.com