Libucl: libucl: denial of service via embedded null byte in ucl input
Priority HIGH 71CWE-125Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · Low · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
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.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00403 34th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2026-0708
- 2026-10-03 Alias added: GHSA-gxf2-jfmj-j5cj
References
More vstakhov Libucl vulnerabilities
- TI-2025-05900 vstakhov libucl ucl_parser.c ucl_parse_multiline_string heap-based overflow CVSS 4.0MEDIUM 4.8
Sources
- CVE-2026-0708 · CVE Program
- CVE-2026-0708 · NVD
- FIRST EPSS
- GHSA-gxf2-jfmj-j5cj · GitHub Advisory Database · CC BY 4.0
- CVE-2026-0708 · Red Hat security data · CC BY 4.0
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