Out-of-Bounds Read in libucl (CVE-2026-0708)
Summary
Vulnerability in libucl (CVE-2026-0708). Confidential information can be exposed externally. Exploitable via ucl_object_emit.
Original description
The description as published by the source.
A flaw was found in libucl. A remote attacker could exploit this by providing a specially crafted Universal Configuration Language (UCL) input that contains a key with an embedded null byte. This can cause a segmentation fault (SEGV fault) in the ucl_object_emit function when parsing and emitting the object, leading to a Denial of Service (DoS) for the affected system.
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-2026-0708 has been found in libucl.
Attackers can target a specific entry point like ucl_object_emit over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 8.3/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "libucl CVE-2026-0708" on the vendor's site.
CVE-2026-0708 (libucl) — CWE-125 / CVSS v3 8.3
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: ucl_object_emit
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 read (CWE-125) exists in libucl. Attackers reach the vulnerable code path via ucl_object_emit without authentication.
Check the vendor advisory for the affected versions of libucl. Attack surface: ucl_object_emit.
Severity: High (CVSS 8.3/10). 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 'libucl' . 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 'libucl' . | 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
libucl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。
References
- advisory patrick@puiterwijk.org
- advisory patrick@puiterwijk.org
- exploit github.com