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VulnerabilityPublished Updated

CVE-2026-46330: Linux kernel · Revert "net/smc: Introduce TCP ULP support

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in df31a6b0a3057e66994ad6ccf5d95b9b9514f033 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:18 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in df31a6b0a3057e66994ad6ccf5d95b9b9514f033, dc824ffc28e5c9d0020b6bee2651b4aceed5b2bf, dc24e03be0e4bb2aad1a9b272c4f86de3b11969a +2
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 9 Jun 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ d7cd421da9da2cc7b4d25b8537f66db5c8331c40, < df31a6b0a3057e66994ad6ccf5d95b9b9514f033
Fixed in
  • df31a6b0a3057e66994ad6ccf5d95b9b9514f033
LinuxLinuxAffected
  • ≥ d7cd421da9da2cc7b4d25b8537f66db5c8331c40, < dc824ffc28e5c9d0020b6bee2651b4aceed5b2bf
Fixed in
  • dc824ffc28e5c9d0020b6bee2651b4aceed5b2bf
LinuxLinuxAffected
  • ≥ d7cd421da9da2cc7b4d25b8537f66db5c8331c40, < dc24e03be0e4bb2aad1a9b272c4f86de3b11969a
Fixed in
  • dc24e03be0e4bb2aad1a9b272c4f86de3b11969a
LinuxLinuxAffected
  • ≥ d7cd421da9da2cc7b4d25b8537f66db5c8331c40, < 74d33525db50d9d95156c79cc874752654e66e70
Fixed in
  • 74d33525db50d9d95156c79cc874752654e66e70
LinuxLinuxAffected
  • ≥ d7cd421da9da2cc7b4d25b8537f66db5c8331c40, < 6c505d95c69e27dbf28fea29dc84d2498d69515c
Fixed in
  • 6c505d95c69e27dbf28fea29dc84d2498d69515c
LinuxLinuxAffected
  • =5.17
Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: Revert "net/smc: Introduce TCP ULP support" This reverts commit d7cd421da9da2cc7b4d25b8537f66db5c8331c40. As reported by Al Viro, the TCP ULP support for SMC is fundamentally broken. The implementation attempts to convert an active TCP socket into an SMC socket by modifying the underlying `struct file`, dentry, and inode in-place, which violates core VFS invariants that assume these structures are immutable for an open file, creating a risk of use after free errors and general system instability. Given the severity of this design flaw and the fact that cleaner alternatives (e.g., LD_PRELOAD, BPF) exist for legacy application transparency, the correct course of action is to remove this feature entirely.

References

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