CVE-2026-99287: Linux kernel · xen-netback: Zero out sring pointers on unmap
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 13 Nov 2026, 14:18 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
Thin evidence
One scorer or noneExploitation evidence
Disclosed: evidence found.
CVE published 10 Nov 2026
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 13 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10linuxpkg:deb/ubuntu/linux?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=stonkingOther 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 that zeroes out the ring pointers after they are unmapped to prevent double unmapping. Users should apply the official patches or updates that include this fix. Since this is a Linux kernel vulnerability, updating to patched kernel versions is the recommended mitigation.
Description
A vulnerability in the Linux kernel's xen-netback component was fixed by zeroing out shared ring (sring) pointers after unmapping them. The issue occurred when the function xenvif_map_frontend_data_rings() failed while a ring was already mapped, leading to multiple unmap attempts on the same pointers without clearing them. This could cause improper cleanup and potential instability. The fix ensures ring pointers are cleared after unmapping to prevent this problem.
References
- ubuntu.com/security/CVE-2026-99287 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-99287 (opens in a new tab)
- git.kernel.org/stable/c/87fd475dc4e354088f6534285388e7b061f54b35 (opens in a new tab)
- git.kernel.org/stable/c/c5f54af611ff6fe1d53fa05d8e87b469dc56122b (opens in a new tab)
- git.kernel.org/stable/c/e7ba61734d6ad6adfd5bf617052e590743211669 (opens in a new tab)