CVE Catalog

CVE-2026-88359

MediumCVSS 6.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.15%

4th percentile - higher than 4% of all known CVEs

Summary

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.

Risk Assessment

An attacker can cause a crash of the YAML parsing process, potentially leading to unavailability of the service or application using libfyaml.

Recommendation

Update libfyaml to a version that includes a fix for this vulnerability. If not possible, limit the size of processed YAML documents or apply a timeout for parsing.

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS