Vulnerability in lz4_flex (CVE-2026-32829)
Summary
Vulnerability in lz4_flex (CVE-2026-32829). Confidential information can be exposed externally. Exploitable via decompress_into.
Original description
The description as published by the source.
lz4_flex is a pure Rust implementation of LZ4 compression/decompression. In versions 0.11.5 and below, and 0.12.0, decompressing invalid LZ4 data can leak sensitive information from uninitialized memory or from previous decompression operations. The library fails to properly validate offset values during LZ4 "match copy operations," allowing out-of-bounds reads from the output buffer. The block-based API functions (decompress_into, decompress_into_with_dict, and others when safe-decode is disabled) are affected, while all frame APIs are unaffected. The impact is potential exposure of sensitive data and secrets through crafted or malformed LZ4 input. This issue has been fixed in versions 0.11.6 and 0.12.1.
Source: NIST National Vulnerability Database NVD
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-2026-32829 has been found in lz4_flex.
Attackers can target a specific entry point like decompress_into over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "lz4_flex CVE-2026-32829" on the vendor's site.
CVE-2026-32829 (lz4_flex) — CWE-201 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: decompress_into / decompress_into_with_dict
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-201) exists in lz4_flex. Attackers reach the vulnerable code path via decompress_into without authentication.
Check the vendor advisory for the affected versions of lz4_flex. Attack surface: decompress_into / decompress_into_with_dict.
Severity: High (CVSS 7.5/10). Confidential information can be exposed externally.
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 'lz4_flex' . 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 'lz4_flex' . | 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
lz4_flex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-2026-32829 rust-lz4-flex
- Ubuntu UBUNTU-CVE-2026-32829 rust-lz4-flex
References
- advisory security-advisories@github.com
- patch security-advisories@github.com
- patch security-advisories@github.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web bugzilla.redhat.com
- web security.access.redhat.com