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Fencer Intel
medium 6.1

CVE-2026-111133 json

libfsapfs through 20260921 Heap Out-of-Bounds Read via libfsapfs_key_encrypted_key_read_data

published 25d ago modified 24d ago also EUVD-2026-102260

cvss
6.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits
0
none known

Summary

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.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
25d ago

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • hackmd.io https://hackmd.io/@haind-pwn/libfsapfs-key-encrypted-key-attribute-oob-read referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 6.9 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
CNA 3.1 6.1 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H
CNA 4.0 6.9 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • libyal libfsapfs

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.