Linux kernel · vsock: Ignore signal/timeout on connect() if
Affects Red HatSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 25 Oct 2026, 19:02 UTC
- 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.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 4 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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 2026-10-25.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Red Hatredhat/kernelpkg:rpm/redhat/kernelOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
An official security update is available from Red Hat as a kpatch live patch module for kernel-5.14.0-611.9.1.el9_7. Applying this update and rebooting the system is required to remediate the vulnerability. Refer to Red Hat's official guidance at https://access.redhat.com/articles/11258 for update instructions. Systems running the affected kernel version should prioritize applying this patch.
Description
In the Linux kernel, the following vulnerability has been resolved: vsock: Ignore signal/timeout on connect() if already established During connect(), acting on a signal/timeout by disconnecting an already established socket leads to several issues: 1. connect() invoking vsock_transport_cancel_pkt() -> virtio_transport_purge_skbs() may race with sendmsg() invoking virtio_transport_get_credit(). This results in a permanently elevated `vvs->bytes_unsent`. Which, in turn, confuses the SOCK_LINGER handling. 2. connect() resetting a connected socket's state may race with socket being placed in a sockmap. A disconnected socket remaining in a sockmap breaks sockmap's assumptions. And gives rise to WARNs. 3. connect() transitioning SS_CONNECTED -> SS_UNCONNECTED allows for a transport change/drop after TCP_ESTABLISHED. Which poses a problem for any simultaneous sendmsg() or connect() and may result in a use-after-free/null-ptr-deref. Do not disconnect socket on signal/timeout. Keep the logic for unconnected sockets: they don't linger, can't be placed in a sockmap, are rejected by sendmsg(). [1]: https://lore.kernel.org/netdev/e07fd95c-9a38-4eea-9638-133e38c2ec9b@rbox.co/ [2]: https://lore.kernel.org/netdev/20250317-vsock-trans-signal-race-v4-0-fc8837f3f1d4@rbox.co/ [3]: https://lore.kernel.org/netdev/60f1b7db-3099-4f6a-875e-af9f6ef194f6@rbox.co/
References
- nvd.nist.gov/vuln/detail/CVE-2025-40248 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-253495.html (opens in a new tab)
- git.kernel.org/stable/c/002541ef650b742a198e4be363881439bb9d86b4 (opens in a new tab)
- git.kernel.org/stable/c/3f71753935d648082a8279a97d30efe6b85be680 (opens in a new tab)
- git.kernel.org/stable/c/5998da5a8208ae9ad7838ba322bccb2bdcd95e81 (opens in a new tab)
- git.kernel.org/stable/c/67432915145848658149683101104e32f9fd6559 (opens in a new tab)
- git.kernel.org/stable/c/ab6b19f690d89ae4709fba73a3c4a7911f495b7a (opens in a new tab)
- git.kernel.org/stable/c/da664101fb4a0de5cb70d2bae6a650df954df2af (opens in a new tab)
- git.kernel.org/stable/c/eeca93f06df89be5a36305b7b9dae1ed65550dfc (opens in a new tab)
- git.kernel.org/stable/c/f1c170cae285e4b8f61be043bb17addc3d0a14b5 (opens in a new tab)