libyal libfsapfs up to 20260921 KEK Attribute libfsapfs_key_encrypted_key_read_data integer underflow

CVSS Meta Temp Score
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CTI Interest Score
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5.4$0-$5k0.81

Summaryinfo

A vulnerability was found in libyal libfsapfs up to 20260921 and classified as problematic. Affected by this vulnerability is the function libfsapfs_key_encrypted_key_read_data of the component KEK Attribute Handler. The manipulation results in integer underflow. This vulnerability is identified as CVE-2026-111133. The attack is only possible with local access. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as problematic, was found in libyal libfsapfs up to 20260921. Affected is the function libfsapfs_key_encrypted_key_read_data of the component KEK Attribute Handler. The manipulation with an unknown input leads to a integer underflow vulnerability. CWE is classifying the issue as CWE-191. The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at hackmd.io. This vulnerability is traded as CVE-2026-111133 since 10/15/2026. The exploitability is told to be easy. The attack needs to be approached locally. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 10/15/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.4

VulDB Base Score: 4.8
VulDB Temp Score: 4.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.1
CNA Vector (VulnCheck): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Integer underflow
CWE: CWE-191 / CWE-189
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

10/15/2026 Advisory disclosed
10/15/2026 +0 days CVE reserved
10/15/2026 +0 days VulDB entry created
10/15/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: hackmd.io
Status: Not defined

CVE: CVE-2026-111133 (🔒)
GCVE (CVE): GCVE-0-2026-111133
GCVE (VulDB): GCVE-100-420816

Entryinfo

Created: 10/15/2026 21:21
Changes: 10/15/2026 21:21 (74)
Complete: 🔍
Cache ID: 216::103

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