Medium severity · published Oct 15, 2026
CVE-2026-111133
libfsapfs through 20260921 Heap Out-of-Bounds Read via libfsapfs_key_encrypted_key_read_data
6.1
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 9% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
libfsapfs · libyal
through 20260921 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-111133
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-111133
github.com
https://github.com/libyal/libfsapfs
github.com
https://github.com/libyal/libfsapfs/blob/4c7c1c21f3cfc7d35f0b34b8a47f1f1562d27bbb/libfsapfs/libfsapfs_key_encrypted_key.c#L321-L333
github.com
https://github.com/libyal/libfsapfs/blob/4c7c1c21f3cfc7d35f0b34b8a47f1f1562d27bbb/libfsapfs/libfsapfs_key_encrypted_key.c#L528-L540
hackmd.io
https://hackmd.io/@haind-pwn/libfsapfs-key-encrypted-key-attribute-oob-read
www.vulncheck.com
https://www.vulncheck.com/advisories/libfsapfs-through-20260921-heap-out-of-bounds-read-via-libfsapfs-key-encrypted-key-read-data