CVE-2025-21669: Linux kernel · vsock/virtio: discard packets if the transport changes
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1080.87~20.04.1 : patch Linux kernel soon.
Data as of 29 Oct 2026, 22:37 UTC
- Patch
- Available – fixed in 5.15.0-1080.87~20.04.1, 5.15.0-1086.95~20.04.1, 5.15.0-1081.90~20.04.1 +62
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 31 Jan 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 29 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7387-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7388-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7389-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7390-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7407-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7421-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7445-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7448-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7458-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7459-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-nvidiapkg:deb/ubuntu/linux-azure-nvidia?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther 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
A patch is available and should be applied. The vulnerability is fixed in Linux kernel versions 5.15.0-1074.77~20.04.1 and later. Users should update their systems to these or newer versions to mitigate the risk. No additional mitigation steps are indicated by the vendor advisory.
Description
CVE-2025-21669 is a high-severity vulnerability in the Linux kernel's vsock/virtio subsystem. It occurs when packets are not discarded after the socket transport changes, potentially leading to a NULL pointer dereference. This can happen if a socket is de-assigned or assigned to another transport, causing unexpected packets to be processed. The issue was fixed in multiple Linux kernel versions starting from 5.15.0-1074.77~20.04.1 and later. The vulnerability has a CVSS score of 7.8, indicating high impact on confidentiality, integrity, and availability.
References
- ubuntu.com/security/CVE-2025-21669 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-21669 (opens in a new tab)
- git.kernel.org/linus/2cb7c756f605ec02ffe562fb26828e4bcc5fdfc1 (opens in a new tab)
- git.kernel.org/stable/c/18a7fc371d1dbf8deff16c2dd9292bcc73f43040 (opens in a new tab)
- git.kernel.org/stable/c/2cb7c756f605ec02ffe562fb26828e4bcc5fdfc1 (opens in a new tab)
- git.kernel.org/stable/c/6486915fa661584d70e8e7e4068c6c075c67dd6d (opens in a new tab)
- git.kernel.org/stable/c/677579b641af109613564460a4e3bdcb16850b61 (opens in a new tab)
- git.kernel.org/stable/c/88244163bc7e7b0ce9dd7bf4c8a563b41525c3ee (opens in a new tab)
- git.kernel.org/stable/c/d88b249e14bd0ee1e46bbe4f456e22e01b8c68de (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7388-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7389-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7390-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7407-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7421-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7445-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7448-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7458-1 (opens in a new tab)