Out-of-bounds Read in Libucl
CVE-2026-0708
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:H.
EPSS exploit prediction
EPSS: 0.004 (30.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 30.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Libucl — versions 3e7f023e184e06f30fb5792dacd9dd0f8b692f1b
- Vstakhov Libucl
Weakness classification (CWE)
References
- access.redhat.com/security/cve/CVE-2026-0708 (Third Party Advisory, vdb-entry)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking, Third Party Advisory, Issue Tracking)
- github.com/vstakhov/libucl/issues/323 (Exploit, Issue Tracking, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-0708?
- CVE-2026-0708 is a high-severity vulnerability in Libucl, classified under Out-of-bounds Read. CVSS score: 8.3/10. Published 2026-03-17.
- How severe is CVE-2026-0708?
- High severity. CVSS v3 base score is 8.3 out of 10.