Linux Kernel up to 7.1.9 libceph cls_lock_client.c decode_locker out-of-bounds

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
9.5	$0-$5k	0.90+

Summaryinfo

A vulnerability was found in Linux Kernel up to 7.1.9. It has been rated as very critical. Affected by this vulnerability is the function decode_locker of the file cls_lock_client.c of the component libceph. This manipulation causes out-of-bounds. This vulnerability is tracked as CVE-2026-80561. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability classified as very critical was found in Linux Kernel up to 7.1.9. Affected by this vulnerability is the function decode_locker of the file cls_lock_client.c of the component libceph. The manipulation with an unknown input leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: libceph: fix multiple unsafe decodes in decode_locker() decode_locker() in cls_lock_client.c contains three unsafe decode operations that allow a malicious or compromised OSD to trigger slab-out-of-bounds reads: 1. ceph_decode_copy() at the locker_id_t name field has no preceding bounds check. With p == end after ceph_start_decoding() accepts struct_len=0, this reads sizeof(ceph_entity_name) = 9 bytes past the validated buffer boundary. 2. *p += sizeof(struct ceph_timespec) after the locker_info_t header is an unchecked pointer advance. A malicious OSD can position p past end, causing all subsequent _safe checks to pass against a bogus boundary. 3. len = ceph_decode_32(p) has no preceding bounds check, and the immediately following *p += len is uncapped. A malicious OSD can send len=0xffffffff, advancing p gigabytes past end and escaping the decode window entirely. Fix all three by replacing bare operations with their safe variants: ceph_decode_copy -> ceph_decode_copy_safe *p += sizeof(...) -> ceph_decode_skip_n ceph_decode_32(p) -> ceph_decode_32_safe *p += len -> ceph_decode_skip_n A new label is added to return -EINVAL on any bounds violation. -EINVAL is appropriate here: the data received from the OSD is structurally malformed, which is an invalid argument to the decode contract regardless of whether the caller or the wire is at fault. Attacker model: a malicious or compromised OSD in a multi-tenant Ceph deployment can trigger this against any kernel client that issues the lock.get_info class method (e.g. during RBD exclusive lock acquisition) without any further privileges beyond OSD session establishment. [ idryomov: use ceph_decode_skip_string() to skip description, trim changelog ]

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2026-80561 since 08/26/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/26/2026).

Upgrading to version 5.10.266, 5.15.217, 6.1.184, 6.6.153, 6.12.105, 6.18.46 or 7.1.10 eliminates this vulnerability. Applying the patch 1ed45c8d96498725eb54f740172f9068d8673906/6265103e78f0ee7e2518de9cf938b94bee9700a0/3c3716dc06a34e4ca7f743f5fcfa07fbc5a11070/fa4aa86fff0c56799c2e3f51a88879053285f4a9/dbfd83f722a78446ec18a476ef7a38e52240b50a/d1bba38574d095f191557d397d9633f08cd966b1/51c8d238fe7236de627ab1a1433694552a904136/437b6551cfcc235eea1d735a874f9d421f555e17 is able to eliminate this problem.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.10.265
• 5.15.216
• 6.1.183
• 6.6.152
• 6.12.104
• 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
• 7.1.0
• 7.1.1
• 7.1.2
• 7.1.3
• 7.1.4
• 7.1.5
• 7.1.6
• 7.1.7
• 7.1.8
• 7.1.9

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: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
VulDB Temp Score: 9.5
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: No
Local: No
Remote: Yes

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 5.10.266/5.15.217/6.1.184/6.6.153/6.12.105/6.18.46/7.1.10
Patch: 1ed45c8d96498725eb54f740172f9068d8673906/6265103e78f0ee7e2518de9cf938b94bee9700a0/3c3716dc06a34e4ca7f743f5fcfa07fbc5a11070/fa4aa86fff0c56799c2e3f51a88879053285f4a9/dbfd83f722a78446ec18a476ef7a38e52240b50a/d1bba38574d095f191557d397d9633f08cd966b1/51c8d238fe7236de627ab1a1433694552a904136/437b6551cfcc235eea1d735a874f9d421f555e17

Timelineinfo

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

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-80561 (🔒)
GCVE (CVE): GCVE-0-2026-80561
GCVE (VulDB): GCVE-100-395857

Entryinfo

Created: 08/26/2026 17:46
Changes: 08/26/2026 17:46 (60)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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