CVE-2025-38616: Linux kernel · tls: handle data disappearing from under the TLS ULP
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 6.8.0-1043.45~22.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1043.45~22.04.1, 6.8.0-1044.50~22.04.1, 6.8.0-1046.53~22.04.1 +36
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 22 Aug 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 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7880-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7889-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7889-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7889-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7889-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7889-6 (opens in a new tab)
- ubuntu.com/security/notices/USN-7934-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | 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-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?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– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: tls: handle data disappearing from under the TLS ULP TLS expects that it owns the receive queue of the TCP socket. This cannot be guaranteed in case the reader of the TCP socket entered before the TLS ULP was installed, or uses some non-standard read API (eg. zerocopy ones). Replace the WARN_ON() and a buggy early exit (which leaves anchor pointing to a freed skb) with real error handling. Wipe the parsing state and tell the reader to retry. We already reload the anchor every time we (re)acquire the socket lock, so the only condition we need to avoid is an out of bounds read (not having enough bytes in the socket for previously parsed record len). If some data was read from under TLS but there's enough in the queue we'll reload and decrypt what is most likely not a valid TLS record. Leading to some undefined behavior from TLS perspective (corrupting a stream? missing an alert? missing an attack?) but no kernel crash should take place.
References
- ubuntu.com/security/CVE-2025-38616 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-38616 (opens in a new tab)
- git.kernel.org/linus/6db015fc4b5d5f63a64a193f65d98da3a7fc811d (opens in a new tab)
- git.kernel.org/stable/c/2fb97ed9e2672b4f6e24ce206ac1a875ce4bcb38 (opens in a new tab)
- git.kernel.org/stable/c/6db015fc4b5d5f63a64a193f65d98da3a7fc811d (opens in a new tab)
- git.kernel.org/stable/c/db3658a12d5ec4db7185ae7476151a50521b7207 (opens in a new tab)
- git.kernel.org/stable/c/eb0336f213fe88bbdb7d2b19c9c9ec19245a3155 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7880-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7889-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7889-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7889-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7889-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7889-6 (opens in a new tab)
- ubuntu.com/security/notices/USN-7934-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7935-1 (opens in a new tab)