Linux Kernel up to 6.19.11 x25_backlog_rcv double free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.6$0-$5k0.00

Summaryinfo

A vulnerability categorized as critical has been discovered in Linux Kernel up to 6.19.11. Affected by this vulnerability is the function x25_backlog_rcv. The manipulation results in double free. This vulnerability is known as CVE-2026-43011. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.19.11. It has been classified as critical. Affected is the function x25_backlog_rcv. The manipulation with an unknown input leads to a double free vulnerability. CWE is classifying the issue as CWE-415. The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: net/x25: Fix potential double free of skb When alloc_skb fails in x25_queue_rx_frame it calls kfree_skb(skb) at line 48 and returns 1 (error). This error propagates back through the call chain: x25_queue_rx_frame returns 1 | v x25_state3_machine receives the return value 1 and takes the else branch at line 278, setting queued=0 and returning 0 | v x25_process_rx_frame returns queued=0 | v x25_backlog_rcv at line 452 sees queued=0 and calls kfree_skb(skb) again This would free the same skb twice. Looking at x25_backlog_rcv: net/x25/x25_in.c:x25_backlog_rcv() { ... queued = x25_process_rx_frame(sk, skb); ... if (!queued) kfree_skb(skb); }

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-43011 since 05/01/2026. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 07/17/2026).

The vulnerability scanner Nessus provides a plugin with the ID 325425 (Ubuntu 24.04 LTS : Linux kernel (NVIDIA) vulnerabilities (USN-8508-1)), 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 5d0aa038a90b30c9bedde0c41c1fdcd98ecb16e9/3f5e3005984645bf5bd129c6b13149879580b1fb/f782dd382203b2a8c4552a628431b7de65a19a7b/143d4fa68ae9efb83b0c55b12cc7f0d03732a2b1/524371398d8463ea7e101fce2cbf3915645d1730/fa1dbc93530b34fab0da9862426fe9c918c74dc0/c87dd137c0dad07cc55f98181ff380b0c23d2878/d10a26aa4d072320530e6968ef945c8c575edf61 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 (325425). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.6
VulDB Meta Temp Score: 7.6

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

CNA Base Score: 9.8
CNA Vector (Linux): 🔒

CVSSv2info

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

Exploitinginfo

Class: Double free
CWE: CWE-415 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 325425
Nessus Name: Ubuntu 24.04 LTS : Linux kernel (NVIDIA) vulnerabilities (USN-8508-1)

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: 5d0aa038a90b30c9bedde0c41c1fdcd98ecb16e9/3f5e3005984645bf5bd129c6b13149879580b1fb/f782dd382203b2a8c4552a628431b7de65a19a7b/143d4fa68ae9efb83b0c55b12cc7f0d03732a2b1/524371398d8463ea7e101fce2cbf3915645d1730/fa1dbc93530b34fab0da9862426fe9c918c74dc0/c87dd137c0dad07cc55f98181ff380b0c23d2878/d10a26aa4d072320530e6968ef945c8c575edf61

Timelineinfo

05/01/2026 Advisory disclosed
05/01/2026 +0 days CVE reserved
05/01/2026 +0 days VulDB entry created
07/17/2026 +77 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-43011 (🔒)
GCVE (CVE): GCVE-0-2026-43011
GCVE (VulDB): GCVE-100-360690

Entryinfo

Created: 05/01/2026 17:58
Updated: 07/17/2026 11:18
Changes: 05/01/2026 17:58 (58), 07/08/2026 09:25 (2), 07/17/2026 11:18 (11)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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