CVE-2026-98122: Linux kernel · vxlan: mdb: Fix use-after-free in vxlan_mdb_remote_src_del()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
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 25 Sep 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
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 that rejects the all-zeros address in vxlan_mdb_is_valid_source(), preventing the use-after-free condition. Users should apply the official patches or upgrade to fixed versions of the linux-hwe-edge kernel. Since this is a kernel vulnerability, updating the kernel to a patched version is the recommended remediation. No additional mitigations are indicated by the vendor advisory.
Description
A use-after-free vulnerability in the Linux kernel's VXLAN multicast database (mdb) handling was resolved. The flaw occurs in vxlan_mdb_remote_src_del() when processing certain multicast source entries with an all-zeros address, leading to a double free and potential memory corruption. This issue affects specific Linux kernel versions used in the linux-hwe-edge product. The vulnerability has a CVSS score of 7.8, indicating a medium severity level with high impact on confidentiality, integrity, and availability. The fix involves rejecting the all-zeros address in the validation function to prevent the erroneous condition. The vulnerability can be triggered by unprivileged users in new user and network namespaces due to the netns-scoped MDB operations. No known exploits are reported in the wild.
References
- ubuntu.com/security/CVE-2026-98122 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98122 (opens in a new tab)
- git.kernel.org/stable/c/74e2a56c82209b0335b53e25f19f9b0590e2483d (opens in a new tab)
- git.kernel.org/stable/c/4aa61c88b4e292e10abdfd791334b8272108d68a (opens in a new tab)
- git.kernel.org/stable/c/71203a41d6fa2fa0ea2f3a7541987958bd3694fd (opens in a new tab)
- git.kernel.org/stable/c/e12c903fd13c6261b98ca18d8f70ac26e739e2f8 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-98122 (opens in a new tab)
- git.kernel.org/stable/c/069d5527bb0f229e528fa88c6b72f15060c373f2 (opens in a new tab)