Linux Kernel up to 6.19.11 AF_ALG Interface sendmsg null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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5.5$0-$5k0.00

Summaryinfo

A vulnerability described as critical has been identified in Linux Kernel up to 6.19.11. The impacted element is the function sendmsg of the component AF_ALG Interface. The manipulation results in null pointer dereference. This vulnerability was named CVE-2026-43043. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.19.11. It has been classified as critical. Affected is the function sendmsg of the component AF_ALG Interface. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: crypto: af-alg - fix NULL pointer dereference in scatterwalk The AF_ALG interface fails to unmark the end of a Scatter/Gather List (SGL) when chaining a new af_alg_tsgl structure. If a sendmsg() fills an SGL exactly to MAX_SGL_ENTS, the last entry is marked as the end. A subsequent sendmsg() allocates a new SGL and chains it, but fails to clear the end marker on the previous SGL's last data entry. This causes the crypto scatterwalk to hit a premature end, returning NULL on sg_next() and leading to a kernel panic during dereference. Fix this by explicitly unmarking the end of the previous SGL when performing sg_chain() in af_alg_alloc_tsgl().

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2026-43043 since 05/01/2026. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 326222 (EulerOS 2.0 SP12 : kernel (EulerOS-SA-2026-2535)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.253, 5.15.203, 6.1.168, 6.6.134, 6.12.81, 6.18.22 or 6.19.12 eliminates this vulnerability. Applying the patch f48d3dd99199180cf37d6253550c55e86372309a/f9acceae7b004956851fd4268edf9f518a9bce04/7195350fb78538c25cd790d703f8f2c73ee0d395/7cdf2c6381b21ab5ccf8116750d5582fcd6c0f49/44eafa39363e8d5dfda6a8c6eb6b45458ed4b948/00cbdec17c15d024a1c5002c7365df7624a18a75/4b03ab0a587ec57eb7ddb5c115d84a42896f60f7/62397b493e14107ae82d8b80938f293d95425bcb 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 (326222). Once again VulDB remains the best source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.7
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 326222
Nessus Name: EulerOS 2.0 SP12 : kernel (EulerOS-SA-2026-2535)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.253/5.15.203/6.1.168/6.6.134/6.12.81/6.18.22/6.19.12
Patch: f48d3dd99199180cf37d6253550c55e86372309a/f9acceae7b004956851fd4268edf9f518a9bce04/7195350fb78538c25cd790d703f8f2c73ee0d395/7cdf2c6381b21ab5ccf8116750d5582fcd6c0f49/44eafa39363e8d5dfda6a8c6eb6b45458ed4b948/00cbdec17c15d024a1c5002c7365df7624a18a75/4b03ab0a587ec57eb7ddb5c115d84a42896f60f7/62397b493e14107ae82d8b80938f293d95425bcb

Timelineinfo

05/01/2026 Advisory disclosed
05/01/2026 +0 days CVE reserved
05/01/2026 +0 days VulDB entry created
07/10/2026 +70 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-43043 (🔒)
GCVE (CVE): GCVE-0-2026-43043
GCVE (VulDB): GCVE-100-360708

Entryinfo

Created: 05/01/2026 18:03
Updated: 07/10/2026 13:19
Changes: 05/01/2026 18:03 (59), 07/10/2026 13:19 (2)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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