CVE-2026-111133

Description

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.

References

• https://github.com/libyal/libfsapfs
• https://github.com/libyal/libfsapfs/blob/4c7c1c21f3cfc7d35f0b34b8a47f1f1562d27bbb/libfsapfs/libfsapfs_key_encrypted_key.c#L321-L333
• https://github.com/libyal/libfsapfs/blob/4c7c1c21f3cfc7d35f0b34b8a47f1f1562d27bbb/libfsapfs/libfsapfs_key_encrypted_key.c#L528-L540
• https://hackmd.io/@haind-pwn/libfsapfs-key-encrypted-key-attribute-oob-read
• https://www.vulncheck.com/advisories/libfsapfs-through-20260921-heap-out-of-bounds-read-via-libfsapfs-key-encrypted-key-read-data