Linux Kernel up to 6.18.18/6.19.8/7.0-rc3 io_uring io_ctx_mark_taskrun privilege escalation

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.
6.5$0-$5k0.00

Summaryinfo

A vulnerability marked as problematic has been reported in Linux Kernel up to 6.18.18/6.19.8/7.0-rc3. Impacted is the function io_ctx_mark_taskrun of the component io_uring. This manipulation causes an unknown weakness. This vulnerability is tracked as CVE-2026-23275. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in Linux Kernel up to 6.18.18/6.19.8/7.0-rc3. Affected by this vulnerability is the function io_ctx_mark_taskrun of the component io_uring. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: io_uring: ensure ctx->rings is stable for task work flags manipulation If DEFER_TASKRUN | SETUP_TASKRUN is used and task work is added while the ring is being resized, it's possible for the OR'ing of IORING_SQ_TASKRUN to happen in the small window of swapping into the new rings and the old rings being freed. Prevent this by adding a 2nd ->rings pointer, ->rings_rcu, which is protected by RCU. The task work flags manipulation is inside RCU already, and if the resize ring freeing is done post an RCU synchronize, then there's no need to add locking to the fast path of task work additions. Note: this is only done for DEFER_TASKRUN, as that's the only setup mode that supports ring resizing. If this ever changes, then they too need to use the io_ctx_mark_taskrun() helper.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-23275 since 01/13/2026. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 06/18/2026).

The vulnerability scanner Nessus provides a plugin with the ID 303223 (Linux Distros Unpatched Vulnerability : CVE-2026-23275), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.18.19, 6.19.9 or 7.0-rc4 eliminates this vulnerability. Applying the patch 7cc4530b3e952d4a5947e1e55d06620d8845d4f5/46dc07d5f31411cc023f3bf1f4a23a07bf6e0ed1/96189080265e6bb5dde3a4afbaf947af493e3f82 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 (303223), EUVD (EUVD-2026-13611) and CERT Bund (WID-SEC-2026-0809). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Google Cloud Platform
  • Amazon Linux 2
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • Open Source Linux Kernel

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.6
VulDB Meta Temp Score: 6.5

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

CNA Base Score: 7.8
CNA Vector (Linux): 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

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

Exploitinginfo

Class: Privilege escalation
CWE: Unknown
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 303223
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-23275

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.18.19/6.19.9/7.0-rc4
Patch: 7cc4530b3e952d4a5947e1e55d06620d8845d4f5/46dc07d5f31411cc023f3bf1f4a23a07bf6e0ed1/96189080265e6bb5dde3a4afbaf947af493e3f82

Timelineinfo

01/13/2026 CVE reserved
03/20/2026 +66 days Advisory disclosed
03/20/2026 +0 days VulDB entry created
06/18/2026 +90 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-23275 (🔒)
GCVE (CVE): GCVE-0-2026-23275
GCVE (VulDB): GCVE-100-352027
EUVD: 🔒
CERT Bund: WID-SEC-2026-0809 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 03/20/2026 09:47
Updated: 06/18/2026 20:23
Changes: 03/20/2026 09:47 (57), 03/20/2026 10:36 (1), 03/20/2026 19:18 (7), 03/23/2026 04:21 (2), 03/26/2026 12:45 (1), 05/04/2026 08:33 (1), 05/23/2026 03:32 (11), 06/18/2026 20:23 (1)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Want to stay up to date on a daily basis?

Enable the mail alert feature now!