Linux Kernel up to 7.0.11 ipc /proc/sysvipc/shm ipc_idr_alloc next_id encoding error

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5.3	$0-$5k	4.03-

Summaryinfo

A vulnerability classified as critical was found in Linux Kernel up to 7.0.11. This impacts the function ipc_idr_alloc of the file /proc/sysvipc/shm of the component ipc. Such manipulation of the argument next_id leads to encoding error. This vulnerability is traded as CVE-2026-52923. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.0.11. It has been rated as critical. Affected by this issue is the function ipc_idr_alloc of the file /proc/sysvipc/shm of the component ipc. The manipulation of the argument next_id with an unknown input leads to a encoding error vulnerability. Using CWE to declare the problem leads to CWE-172. The product does not properly encode or decode the data, resulting in unexpected values. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: ipc: limit next_id allocation to the valid ID range The checkpoint/restore sysctl path can request the next SysV IPC id through ids->next_id. ipc_idr_alloc() currently forwards that request to idr_alloc() with an open-ended upper bound. If the valid tail of the SysV IPC id space is full, the allocation can spill beyond ipc_mni. The returned SysV IPC id still uses the normal index encoding, so later lookup and removal can target the wrong slot. This leaves the real IDR entry behind and breaks the IDR state for the object. The bug is in ipc_idr_alloc() in the checkpoint/restore path. 1. ids->next_id is passed to: idr_alloc(&ids->ipcs_idr, new, ipcid_to_idx(next_id), 0, ...) 2. The zero upper bound makes the allocation effectively open-ended. Once the valid SysV IPC tail is occupied, idr_alloc() can spill past ipc_mni and allocate an entry beyond the valid IPC id range. 3. The new object id is still encoded with the narrower SysV IPC index width: new->id = (new->seq << ipcmni_seq_shift()) + idx 4. Later removal goes through ipc_rmid(), which uses: ipcid_to_idx(ipcp->id) That truncates the real IDR index. An object actually stored at a high index can then be removed as if it lived at a low in-range index. 5. For shared memory, shm_destroy() frees the current object anyway, but the real high IDR slot is left behind as a dangling pointer. 6. A subsequent walk of /proc/sysvipc/shm reaches the stale IDR entry and dereferences freed memory. Prevent this by bounding the requested allocation to ipc_mni so the checkpoint/restore path fails once the valid range is exhausted.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-52923 since 06/09/2026. 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 06/25/2026).

The vulnerability scanner Nessus provides a plugin with the ID 322536 (Linux Distros Unpatched Vulnerability : CVE-2026-52923), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.35 or 7.0.12 eliminates this vulnerability. Applying the patch 3bbe2bb9111ce6967a951bfac79af142d816fae5/8c58a92849175f5e2ab7bc2734b3b89afe79f6ef/af24e202b543ded8a34f1d5d3db54eb916173f04/157ce2c6836ce0ff19108a819f38df061345425f/41058d4c3f63ab64901560a704882e0565f4e456/a3cc795129e5ec0f8948653a3bf471e7d8852f5e/bd4be70669af55b974860d13680348cfdf50bbed/fa0b9b2b7ae3539908d69c2b9ac0d144d9bc5139 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (322536) and CERT Bund (WID-SEC-2026-2056). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.10.258
• 5.15.209
• 6.1.175
• 6.6.142
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.12.35
• 6.12.36
• 6.12.37
• 6.12.38
• 6.12.39
• 6.12.40
• 6.12.41
• 6.12.42
• 6.12.43
• 6.12.44
• 6.12.45
• 6.12.46
• 6.12.47
• 6.12.48
• 6.12.49
• 6.12.50
• 6.12.51
• 6.12.52
• 6.12.53
• 6.12.54
• 6.12.55
• 6.12.56
• 6.12.57
• 6.12.58
• 6.12.59
• 6.12.60
• 6.12.61
• 6.12.62
• 6.12.63
• 6.12.64
• 6.12.65
• 6.12.66
• 6.12.67
• 6.12.68
• 6.12.69
• 6.12.70
• 6.12.71
• 6.12.72
• 6.12.73
• 6.12.74
• 6.12.75
• 6.12.76
• 6.12.77
• 6.12.78
• 6.12.79
• 6.12.80
• 6.12.81
• 6.12.82
• 6.12.83
• 6.12.84
• 6.12.85
• 6.12.86
• 6.12.87
• 6.12.88
• 6.12.89
• 6.12.90
• 6.12.91
• 6.12.92
• 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
• 7.0.0
• 7.0.1
• 7.0.2
• 7.0.3
• 7.0.4
• 7.0.5
• 7.0.6
• 7.0.7
• 7.0.8
• 7.0.9
• 7.0.10
• 7.0.11

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: 5.5
VulDB Meta Temp Score: 5.3

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

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

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

Exploitinginfo

Class: Encoding error
CWE: CWE-172
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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

Nessus ID: 322536
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-52923

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.259/5.15.210/6.1.176/6.6.143/6.12.93/6.18.35/7.0.12
Patch: 3bbe2bb9111ce6967a951bfac79af142d816fae5/8c58a92849175f5e2ab7bc2734b3b89afe79f6ef/af24e202b543ded8a34f1d5d3db54eb916173f04/157ce2c6836ce0ff19108a819f38df061345425f/41058d4c3f63ab64901560a704882e0565f4e456/a3cc795129e5ec0f8948653a3bf471e7d8852f5e/bd4be70669af55b974860d13680348cfdf50bbed/fa0b9b2b7ae3539908d69c2b9ac0d144d9bc5139

Timelineinfo

06/09/2026 CVE reserved
06/24/2026 +15 days Advisory disclosed
06/24/2026 +0 days VulDB entry created
06/25/2026 +1 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-52923 (🔒)
GCVE (CVE): GCVE-0-2026-52923
GCVE (VulDB): GCVE-100-373184
CERT Bund: WID-SEC-2026-2056 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 06/24/2026 10:07
Updated: 06/25/2026 05:00
Changes: 06/24/2026 10:07 (61), 06/24/2026 18:04 (7), 06/25/2026 05:00 (2)
Complete: 🔍
Cache ID: 216::103

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