CVE catalog
CVE-2026-88359
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 functio
- Severity
- Medium · CVSS 6.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - Published
- Updated
- Source
- [NVD] · [CVE record]
- EPSS
- 0.30% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | libfyaml | sid | 0.9.4-1 | vulnerable |
| Debian | libfyaml | forky | 0.9.4-1 | vulnerable |
| Debian | libfyaml | trixie | 0.8-1 | vulnerable |
| Debian | libfyaml | bookworm | 0.7.12-2 | vulnerable |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | libfyaml | source | sid | (unfixed) | not yet assigned | Not reported | [1149055] |
| Debian | libfyaml | source | forky | (unfixed) | not yet assigned | Not reported | [1149055] |
| Debian | libfyaml | source | trixie | (unfixed) | not yet assigned | Not reported | [1149055] |
| Debian | libfyaml | source | bookworm | (unfixed) | not yet assigned | Not reported | [1149055] |
Notes
[trixie] libfyaml: Minor issue [bookworm] libfyaml: Minor issue
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [libfyaml0]Affected
Source package: [libfyaml]
Details (2)
0.7.12-2· amd64 · bookwormAffected
nvd · libfyaml · debian · bookworm; nvd · libfyaml · debian · 12
0.7.12-2· arm64 · bookwormAffected
nvd · libfyaml · debian · bookworm; nvd · libfyaml · debian · 12
- [libfyaml-dev]Affected
Source package: [libfyaml]
Details (2)
0.7.12-2· amd64 · bookwormAffected
nvd · libfyaml · debian · bookworm; nvd · libfyaml · debian · 12
0.7.12-2· arm64 · bookwormAffected
nvd · libfyaml · debian · bookworm; nvd · libfyaml · debian · 12
- [libfyaml-utils]Affected
Source package: [libfyaml]
Details (2)
0.7.12-2· amd64 · bookwormAffected
nvd · libfyaml · debian · bookworm; nvd · libfyaml · debian · 12
0.7.12-2· arm64 · bookwormAffected
nvd · libfyaml · debian · bookworm; nvd · libfyaml · debian · 12
[Debian 13 (Trixie)]
- [libfyaml0]Affected
Source package: [libfyaml]
Details (2)
0.8-1+b2· amd64 · trixieAffected
nvd · libfyaml · debian · 13
0.8-1+b2· arm64 · trixieAffected
nvd · libfyaml · debian · 13
- [libfyaml-dev]Affected
Source package: [libfyaml]
Details (2)
0.8-1+b2· amd64 · trixieAffected
nvd · libfyaml · debian · 13
0.8-1+b2· arm64 · trixieAffected
nvd · libfyaml · debian · 13
- [libfyaml-utils]Affected
Source package: [libfyaml]
Details (2)
0.8-1+b2· amd64 · trixieAffected
nvd · libfyaml · debian · 13
0.8-1+b2· arm64 · trixieAffected
nvd · libfyaml · debian · 13
Observed:
References
- [https://nvd.nist.gov/vuln/detail/CVE-2026-88359]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-88359]
- [https://security-tracker.debian.org/tracker/CVE-2026-88359]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-88359.json]
[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]