Vulnerability · Published Mar 17, 2026 · Assigned by fedora
CVE-2026-0708Libucl: libucl: denial of service via embedded null byte in ucl input
High 8.3
In plain English
A high-severity out-of-bounds read in libucl from libucl. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 35% of all known vulnerabilities).
Severity (CVSS 3.1)8.3High
Exploit odds (30 days)0.4%top 65.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
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.
Affected products (as reported)
Weakness: CWE-125 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:H
References
- https://access.redhat.com/security/cve/CVE-2026-0708 vdb-entry, x_refsource_REDHAT
- RHBZ#2427770 issue-tracking, x_refsource_REDHAT
- https://github.com/vstakhov/libucl/issues/323