CVE-2026-98261: Linux kernel · cifs: Fix server use-after-free in cifs_chan_skip_or_disable()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.1 High · end of life, no fix coming : replace or isolate Linux kernel; no fix will be released.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 34% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- None coming – the product is end of life
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 6 Oct 2026
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
No fix will be released: Linux kernel is end of life. Replace it, or isolate it from untrusted networks until you can.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther 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 fix is available for this vulnerability. Users should apply the updated Linux kernel versions that include the patch resolving this use-after-free issue in the CIFS code. No additional mitigation steps are indicated beyond applying the official fix.
Description
A use-after-free vulnerability in the Linux kernel's CIFS implementation was fixed. The flaw occurred in the cifs_chan_skip_or_disable() function when handling secondary channels no longer supported by the server. The function dropped the channel reference before safely signaling the server, potentially leading to use of freed memory. This could cause system crashes or allow an attacker to execute arbitrary code with kernel privileges.
References
- ubuntu.com/security/CVE-2026-98261 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98261 (opens in a new tab)
- git.kernel.org/linus/717e0a25036b6c92cecace30913b2d874a4c22b8 (opens in a new tab)
- git.kernel.org/stable/c/0338489960ddad6368bce55e8adbc176c523093d (opens in a new tab)
- git.kernel.org/stable/c/717e0a25036b6c92cecace30913b2d874a4c22b8 (opens in a new tab)
- git.kernel.org/stable/c/7a1b27780b113583a94256d58dabfe7c0d9286e7 (opens in a new tab)
- git.kernel.org/stable/c/edd52eae5fcfb8433b6bb0e7cd98db438fe01227 (opens in a new tab)
- git.kernel.org/stable/c/fcc0a935bb6e37ecbf7e4335061309f896f35780 (opens in a new tab)