Linux Kernel up to 6.19.5 bitmap write_page use after free

CVSS Meta Temp Score
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CTI Interest Score
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6.2$5k-$25k0.00

Summaryinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.19.5. This vulnerability affects the function write_page of the component bitmap. The manipulation results in use after free. This vulnerability is reported as CVE-2026-43163. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.19.5. Affected is the function write_page of the component bitmap. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: md/bitmap: fix GPF in write_page caused by resize race A General Protection Fault occurs in write_page() during array resize: RIP: 0010:write_page+0x22b/0x3c0 [md_mod] This is a use-after-free race between bitmap_daemon_work() and __bitmap_resize(). The daemon iterates over `bitmap->storage.filemap` without locking, while the resize path frees that storage via md_bitmap_file_unmap(). `quiesce()` does not stop the md thread, allowing concurrent access to freed pages. Fix by holding `mddev->bitmap_info.mutex` during the bitmap update.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2026-43163 since 05/01/2026. The exploitability is told to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 05/21/2026).

The vulnerability scanner Nessus provides a plugin with the ID 315949 (RHEL 9 : kernel (RHSA-2026:19568)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.252, 5.15.202, 6.1.165, 6.6.128, 6.12.75, 6.18.16 or 6.19.6 eliminates this vulnerability. Applying the patch 140cc839fbeb1ddb33a8da8811b716d88d3905b7/ebcacc7ca22d5e8a03a970f0621ae1d1356b9ae8/d3af62411e19752c663fe4f424dbf49d95a4cc7c/d92b8fac294b5f915c50e65ce4ae2262e53614ec/a437e3bf30e32846079e470c1ba5ee790bccdf89/9a6f8cd28bb9bb6ed86a6df19331fb08016dee7f/5f73c8b33df9a605a591eab72d43a969600c1f8c/46ef85f854dfa9d5226b3c1c46493d79556c9589 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 vulnerability database at Tenable (315949). Once again VulDB remains the best source for vulnerability data.

Productinfo

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Version

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.2

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 4.7
NVD Vector: 🔒

CVSSv2info

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

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 315949
Nessus Name: RHEL 9 : kernel (RHSA-2026:19568)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.252/5.15.202/6.1.165/6.6.128/6.12.75/6.18.16/6.19.6
Patch: 140cc839fbeb1ddb33a8da8811b716d88d3905b7/ebcacc7ca22d5e8a03a970f0621ae1d1356b9ae8/d3af62411e19752c663fe4f424dbf49d95a4cc7c/d92b8fac294b5f915c50e65ce4ae2262e53614ec/a437e3bf30e32846079e470c1ba5ee790bccdf89/9a6f8cd28bb9bb6ed86a6df19331fb08016dee7f/5f73c8b33df9a605a591eab72d43a969600c1f8c/46ef85f854dfa9d5226b3c1c46493d79556c9589

Timelineinfo

05/01/2026 CVE reserved
05/06/2026 +5 days Advisory disclosed
05/06/2026 +0 days VulDB entry created
05/21/2026 +15 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-43163 (🔒)
GCVE (CVE): GCVE-0-2026-43163
GCVE (VulDB): GCVE-100-361452

Entryinfo

Created: 05/06/2026 16:47
Updated: 05/21/2026 09:12
Changes: 05/06/2026 16:47 (59), 05/17/2026 14:14 (11), 05/21/2026 09:12 (2)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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