Out-of-bounds Read in Libyal Libfsapfs
CVE-2026-111133
libfsapfs through 20260921 contains an integer underflow in libfsapfs_key_encrypted_key_read_data() that allows attackers to trigger heap out-of-bounds reads via crafted KEK attributes. Attackers can supply a crafted encrypted APFS image with malformed HMAC or wrapped KEK attribute lengths to crash fsapfsinfo, pyfsapfs, dfVFS or plaso and read adjacent heap memory before password checks.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- hackmd.io/@haind-pwn/libfsapfs-key-encrypted-key-attribute-oob-read (technical-description)
- github.com/libyal/libfsapfs/blob/4c7c1c21f3cfc7d35f0b34b8a47f1f1562d27bbb/libfs… (technical-description)
- github.com/libyal/libfsapfs/blob/4c7c1c21f3cfc7d35f0b34b8a47f1f1562d27bbb/libfs… (technical-description)
- github.com/libyal/libfsapfs (product)
- www.vulncheck.com/advisories/libfsapfs-through-20260921-heap-out-of-bounds-read… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-111133?
- CVE-2026-111133 is a medium-severity vulnerability in Libyal Libfsapfs, classified under Out-of-bounds Read. CVSS score: 6.1/10. Published 2026-10-15.
- How severe is CVE-2026-111133?
- Medium severity. CVSS v3 base score is 6.1 out of 10.