CVE-2026-0708 Libucl: libucl: denial of service via embedded null byte in ucl input
A remote attacker can cause a denial of service in applications using libucl by providing crafted UCL input with embedded null bytes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-0708?
CVE-2026-0708 is a high-severity denial of service vulnerability in libucl, published on 17 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
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.
Weakness: CWE-125
Which versions are affected by CVE-2026-0708?
It affects 1 product.
Products include Vstakhov Libucl.
How do I fix CVE-2026-0708?
No fix has been published for CVE-2026-0708 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-0708 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-0708 exists.
Other vulnerabilities in libucl
Sources
Also known as GHSA-gxf2-jfmj-j5cj.