CVE-2026-88359 Denial of service in n/a
A stack exhaustion vulnerability in libfyaml allows attackers to cause a denial of service via crafted YAML documents.
- 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-2026-88359?
CVE-2026-88359 is a medium-severity denial of service vulnerability in n/a, published on 24 Sep 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
libfyaml 0.9.6 contains a stack exhaustion vulnerability in fy_atom_iter_format(). When processing a specially crafted YAML document containing a very large literal or folded block scalar, the function repeatedly grows an internal buffer using alloca() inside a loop. The allocated stack memory is not released until the function returns, causing cumulative stack growth that can exceed the process stack limit and result in SIGSEGV and denial of service.
Weakness: CWE-770
Which versions are affected by CVE-2026-88359?
How do I fix CVE-2026-88359?
No fix has been published for CVE-2026-88359 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-2026-88359 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-88359 exists.
Sources
Also known as DEBIAN-CVE-2026-88359, GHSA-3qj9-89fg-m5cw, UBUNTU-CVE-2026-88359.