Linux Kernel up to 6.18.49/7.2.3 dm-pcache cache_key_decode key_num out-of-bounds

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1.9	$0-$5k	0.00+

Summaryinfo

A vulnerability, which was classified as problematic, was found in Linux Kernel up to 6.18.49/7.2.3. The impacted element is the function cache_key_decode of the component dm-pcache. The manipulation of the argument key_num results in out-of-bounds. This vulnerability is cataloged as CVE-2026-80961. The attack must be initiated from a local position. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.49/7.2.3. It has been classified as problematic. Affected is the function cache_key_decode of the component dm-pcache. The manipulation of the argument key_num with an unknown input leads to a out-of-bounds vulnerability. CWE is classifying the issue as CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: dm-pcache: validate kset key_num and intra-segment bounds Two more fields decoded from the cache device go unbounded. The kset key_num drives cache_kset_crc() and the replay loop in cache_replay(), the writeback worker and the GC worker, but only the magic and a fixed-seed CRC are checked first, so a non-last kset whose key_num exceeds the PCACHE_KSET_KEYS_MAX buffer reads past its end before the CRC compare. A key's intra-segment offset and length in cache_key_decode() are taken verbatim, so a key running past its segment is replayed into the cache tree and the data CRC check and every later read hit then copy adjacent persistent memory into the caller's bio -- an out-of-bounds read that leaks to user space. Both fields are controlled by whoever supplies the cache device (CAP_SYS_ADMIN); the CRC seed is public. Add kset_onmedia_valid() to bound key_num before any kset read, and reject a key whose offset plus length, computed in 64 bits, exceeds the segment data_size. Valid metadata is unaffected.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2026-80961 since 08/26/2026. The exploitability is told to be easy. The attack needs to be approached locally. Additional levels of successful authentication are needed for exploitation. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available.

Upgrading to version 6.18.50, 7.2.4 or 7.3-rc1 eliminates this vulnerability. Applying the patch d8caf96040a06096276ab72f5e1e8547c014c564/5ac38f4b4862fad6e7270fde5c3356a822ce74ca/f11deb032fd84081e7831cffcba895d893054a22 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.18.23
• 6.18.24
• 6.18.25
• 6.18.26
• 6.18.27
• 6.18.28
• 6.18.29
• 6.18.30
• 6.18.31
• 6.18.32
• 6.18.33
• 6.18.34
• 6.18.35
• 6.18.36
• 6.18.37
• 6.18.38
• 6.18.39
• 6.18.40
• 6.18.41
• 6.18.42
• 6.18.43
• 6.18.44
• 6.18.45
• 6.18.46
• 6.18.47
• 6.18.48
• 6.18.49
• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 2.0
VulDB Meta Temp Score: 1.9

VulDB Base Score: 2.0
VulDB Temp Score: 1.9
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

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

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.18.50/7.2.4/7.3-rc1
Patch: d8caf96040a06096276ab72f5e1e8547c014c564/5ac38f4b4862fad6e7270fde5c3356a822ce74ca/f11deb032fd84081e7831cffcba895d893054a22

Timelineinfo

08/26/2026 CVE reserved
09/11/2026 +16 days Advisory disclosed
09/11/2026 +0 days VulDB entry created
09/11/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-80961 (🔒)
GCVE (CVE): GCVE-0-2026-80961
GCVE (VulDB): GCVE-100-402684

Entryinfo

Created: 09/11/2026 23:39
Changes: 09/11/2026 23:39 (60)
Complete: 🔍
Cache ID: 216::103

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Discussion

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