Linux Kernel up to 7.1.8 smc smc_rx_splice use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.5$5k-$25k0.87-

Summaryinfo

A vulnerability labeled as very critical has been found in Linux Kernel up to 6.1.182/6.6.151/6.12.103/6.18.44/7.1.8. This affects the function smc_rx_splice of the component smc. Such manipulation leads to use after free. This vulnerability is listed as CVE-2026-74631. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 6.1.182/6.6.151/6.12.103/6.18.44/7.1.8. Affected by this issue is the function smc_rx_splice of the component smc. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: net: smc: fix splice entry lifetime imbalance in smc_rx_splice smc_rx_splice() passes pages to splice_to_pipe() before taking the references that cover the lifetime of each splice entry. In the VM-backed RMB path, splice_to_pipe() may drop unqueued entries through smc_rx_spd_release(), while queued entries are released later via the pipe buffer callback. The old post-splice accounting also derives the number of queued VM pages from an offset mutated while building the descriptor, and a multi-page splice pairs one sock_hold() with multiple sock_put() calls. Take the page and socket references for every candidate entry before splice_to_pipe(), and drop the matching private state, page reference, and socket reference from smc_rx_spd_release() for entries that never get queued. This fixes a refcount imbalance that can underflow page refcounts and trigger a use-after-free.

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2026-74631 since 08/15/2026. The exploitation is known to be easy. The attack may be launched remotely. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 08/22/2026).

Upgrading to version 6.1.183, 6.6.152, 6.12.104, 6.18.45 or 7.1.9 eliminates this vulnerability. Applying the patch c841789e456ec6751342fa800639ce8e82ff0e6b/af02c67ce654356c58db20a0bb2db33ace3b07a8/ca8342b5fc24c249fdb998468f6a168b457c67e5/0b7d54cedea5cb158e21925ae0c6c2f5c87ed2a0/4515c78f4d9fd577270f012efeb062ea58b3682d/5d9686af2976741bbd79b150d1c9e60b81e7f12e is able to eliminate this problem.

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Productinfo

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Version

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
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
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.1.183/6.6.152/6.12.104/6.18.45/7.1.9
Patch: c841789e456ec6751342fa800639ce8e82ff0e6b/af02c67ce654356c58db20a0bb2db33ace3b07a8/ca8342b5fc24c249fdb998468f6a168b457c67e5/0b7d54cedea5cb158e21925ae0c6c2f5c87ed2a0/4515c78f4d9fd577270f012efeb062ea58b3682d/5d9686af2976741bbd79b150d1c9e60b81e7f12e

Timelineinfo

08/15/2026 CVE reserved
08/22/2026 +7 days Advisory disclosed
08/22/2026 +0 days VulDB entry created
08/22/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-74631 (🔒)
GCVE (CVE): GCVE-0-2026-74631
GCVE (VulDB): GCVE-100-394418

Entryinfo

Created: 08/22/2026 18:29
Changes: 08/22/2026 18:29 (59)
Complete: 🔍
Cache ID: 216::103

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