# CVE-2026-116729: libfvde through 20260923 Heap Out-of-Bounds Read via libfvde_encrypted_metadata_read_type_0x001a

Status: published. Published: 2026-10-26. Updated: 2026-11-02.

libfvde through 20260923 contains a heap out-of-bounds read vulnerability in libfvde_encrypted_metadata_read_type_0x001a() caused by an unbounded strlen on embedded XML plist data. Attackers can supply a crafted FileVault 2 volume with non-NUL-terminated plist data, causing libfvde_volume_open() to read past the heap block buffer.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/libyal/libfvde/commit/c2676fe49d0da44d66e7d750e72c57d2670f0b8f

## Affected products and versions

- libyal / libfvde (libyal/libfvde): ≥ 0; ≤ 20260923 (affected, custom). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 4.8 (medium); CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 3.3 (low); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: 0.13% as of 2026-11-02; percentile 2.77%

- SSVC: exploitation poc; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-125

## Exploit evidence

- exploit: https://hackmd.io/@haindpwn/libfvde-encrypted-metadata-oob-read (ADP: CISA-ADP)

## References

- https://github.com/libyal/libfvde/issues/70 (CNA: VulnCheck; issue-tracking)

- https://github.com/libyal/libfvde (CNA: VulnCheck; product)

- https://github.com/libyal/libfvde/commit/c2676fe49d0da44d66e7d750e72c57d2670f0b8f (CNA: VulnCheck; patch)

- https://github.com/libyal/libfvde/blob/20260923/libfvde/libfvde_encrypted_metadata.c#L2786-L2792 (CNA: VulnCheck; technical-description)

- https://hackmd.io/@haindpwn/libfvde-encrypted-metadata-oob-read (CNA: VulnCheck; third-party-advisory)

- https://www.vulncheck.com/advisories/libfvde-through-20260923-heap-out-of-bounds-read-via-libfvde-encrypted-metadata-read-type-0x001a (CNA: VulnCheck; third-party-advisory)

- https://hackmd.io/@haindpwn/libfvde-encrypted-metadata-oob-read (ADP: CISA-ADP; exploit)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-116729; retrieved 2026-11-02; source updated 2026-11-02

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-116729; retrieved 2026-11-02; source updated Not reported

Revision: f2699142ef1588e6b07a7956170b1efa59b30edfff173314d07743dd19ebf106

Canonical: https://y2.dev/cve/CVE-2026-116729

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