CVE-2025-68263: Linux kernel · ksmbd: ipc: fix use-after-free in ipc_msg_send_request
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 5.15.0-1111.118~20.04.1 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 38% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1111.118~20.04.1, 5.15.0-1116.125~20.04.1, 5.15.0-1111.121~20.04.1 +71
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 16 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 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux@6.17.0-19.19?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1009.9?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1010.10?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1009.9?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1009.9?arch=source&distro=questingOther 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 from the vendor. Users should update their Linux kernel packages to the fixed versions listed in the Ubuntu security advisories USN-8094-1 and USN-8094-2 and reboot their systems to apply the fixes. Due to an ABI change, recompilation and reinstallation of third-party kernel modules may be required. No additional mitigations are indicated by the vendor advisory.
Description
A critical use-after-free vulnerability (CVE-2025-68263) in the Linux kernel's ksmbd IPC subsystem was resolved. The flaw involved a race condition where ipc_msg_send_request() could free memory while another handler was still accessing it, leading to a slab-use-after-free detected by KASAN. This vulnerability affects Linux kernel versions prior to certain 5.15.x releases on Ubuntu 20.04.1. The issue has been fixed by ensuring proper locking around the shared data structures. The vulnerability has a CVSS score of 9.8, indicating high impact on confidentiality, integrity, and availability. A patch is available and users are advised to update and reboot to apply the fix. The vendor advisory also covers many other Linux kernel vulnerabilities fixed in the same update.
References
- ubuntu.com/security/CVE-2025-68263 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-68263 (opens in a new tab)
- git.kernel.org/linus/1fab1fa091f5aa97265648b53ea031deedd26235 (opens in a new tab)
- git.kernel.org/stable/c/1fab1fa091f5aa97265648b53ea031deedd26235 (opens in a new tab)
- git.kernel.org/stable/c/5ac763713a1ef8f9a8bda1dbd81f0318d67baa4e (opens in a new tab)
- git.kernel.org/stable/c/759c8c30cfa8706c518e56f67971b1f0932f4b9b (opens in a new tab)
- git.kernel.org/stable/c/8229c6ca50cea701e25a7ee25f48441b582ec5fa (opens in a new tab)
- ubuntu.com/security/notices/USN-8094-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8094-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8094-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8094-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8094-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8152-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8179-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8184-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8179-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8185-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8179-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8203-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8204-1 (opens in a new tab)