Linux Kernel up to 6.18.41/7.1.5/7.2-rc3 xfrm validate_xmit_skb_list use after free

CVSS Meta Temp Score
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CTI Interest Score
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9.5$5k-$25k0.00

Summaryinfo

A vulnerability marked as very critical has been reported in Linux Kernel up to 6.18.41/7.1.5/7.2-rc3. The affected element is the function validate_xmit_skb_list of the component xfrm. Performing a manipulation results in use after free. This vulnerability is reported as CVE-2026-68426. The attack is possible to be carried out remotely. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as very critical has been found in Linux Kernel up to 6.18.41/7.1.5/7.2-rc3. This affects the function validate_xmit_skb_list of the component xfrm. 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. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: xfrm: fix stale skb->prev after async crypto steals a GSO segment skb_gso_segment() leaves the segment list head with ->prev pointing at the last segment, an invariant validate_xmit_skb_list() relies on when it sets its tail pointer (tail = skb->prev). When validate_xmit_xfrm() walks a GSO list and some segments are stolen by async crypto (->xmit() returns -EINPROGRESS), those segments are unlinked from the list but the head ->prev is never updated. If the last segment is the one stolen, the returned head still has ->prev pointing at it, even though it is now owned by the crypto engine and may be freed. validate_xmit_skb_list() later does tail->next = skb, writing through that stale pointer -- a use-after-free. Repoint skb->prev at the last retained segment before returning.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-68426 since 07/30/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/17/2026).

The vulnerability scanner Nessus provides a plugin with the ID 346426 (Oracle Linux 10 : ELSA-2026-67471-0: / kernel (ELSA-2026-674710)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.18.42, 7.1.6 or 7.2-rc4 eliminates this vulnerability. Applying the patch 33e1b0d25ca0d2818c635ff80e6aa0d295e08a98/bbca7cc3b2b4b10afbfee99b81d9ee78f5423046/3f4c3919baf0944ad96580467c302bc6c7758b00 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (346426). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
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: Use after free
CWE: CWE-416 / 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: 346426
Nessus Name: Oracle Linux 10 : ELSA-2026-67471-0: / kernel (ELSA-2026-674710)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.18.42/7.1.6/7.2-rc4
Patch: 33e1b0d25ca0d2818c635ff80e6aa0d295e08a98/bbca7cc3b2b4b10afbfee99b81d9ee78f5423046/3f4c3919baf0944ad96580467c302bc6c7758b00

Timelineinfo

07/30/2026 CVE reserved
08/10/2026 +11 days Advisory disclosed
08/10/2026 +0 days VulDB entry created
09/17/2026 +38 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-68426 (🔒)
GCVE (CVE): GCVE-0-2026-68426
GCVE (VulDB): GCVE-100-387657

Entryinfo

Created: 08/10/2026 17:16
Updated: 09/17/2026 06:51
Changes: 08/10/2026 17:16 (59), 09/17/2026 06:51 (2)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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