Skip to main content
VulnerabilityPublished Updated

CVE-2026-98122: Linux kernel · vxlan: mdb: Fix use-after-free in vxlan_mdb_remote_src_del()

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in e12c903fd13c6261b98ca18d8f70ac26e739e2f8 : patch Linux kernel soon.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
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.
Patch
Available – fixed in e12c903fd13c6261b98ca18d8f70ac26e739e2f8, 71203a41d6fa2fa0ea2f3a7541987958bd3694fd, 74e2a56c82209b0335b53e25f19f9b0590e2483d +2
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 25 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ a3a48de5eade770e911d35291217bdd69ce04ef1, < e12c903fd13c6261b98ca18d8f70ac26e739e2f8
Fixed in
  • e12c903fd13c6261b98ca18d8f70ac26e739e2f8
LinuxLinuxAffected
  • ≥ a3a48de5eade770e911d35291217bdd69ce04ef1, < 71203a41d6fa2fa0ea2f3a7541987958bd3694fd
Fixed in
  • 71203a41d6fa2fa0ea2f3a7541987958bd3694fd
LinuxLinuxAffected
  • ≥ a3a48de5eade770e911d35291217bdd69ce04ef1, < 74e2a56c82209b0335b53e25f19f9b0590e2483d
Fixed in
  • 74e2a56c82209b0335b53e25f19f9b0590e2483d
LinuxLinuxAffected
  • ≥ a3a48de5eade770e911d35291217bdd69ce04ef1, < 069d5527bb0f229e528fa88c6b72f15060c373f2
Fixed in
  • 069d5527bb0f229e528fa88c6b72f15060c373f2
LinuxLinuxAffected
  • ≥ a3a48de5eade770e911d35291217bdd69ce04ef1, < 4aa61c88b4e292e10abdfd791334b8272108d68a
Fixed in
  • 4aa61c88b4e292e10abdfd791334b8272108d68a
LinuxLinuxAffected
  • =6.4
Fixed in–

AI-suggested

A fix is available and has been applied in the Linux kernel source code by rejecting the all-zeros address in vxlan_mdb_is_valid_source(). Users and administrators should update to the fixed Linux kernel versions identified by the commits e12c903fd13c6261b98ca18d8f70ac26e739e2f8, 71203a41d6fa2fa0ea2f3a7541987958bd3694fd, 74e2a56c82209b0335b53e25f19f9b0590e2483d, 069d5527bb0f229e528fa88c6b72f15060c373f2, or 4aa61c88b4e292e10abdfd791334b8272108d68a. No additional mitigations are indicated by the vendor advisory.

Description

CVE-2026-98122 is a use-after-free vulnerability in the Linux kernel's VXLAN multicast database (mdb) handling, specifically in the function vxlan_mdb_remote_src_del(). The flaw arises when the all-zeros address is accepted as a valid source, causing key aliasing that leads to freeing an entry twice. This can result in a kernel crash or potential escalation of privileges. The vulnerability affects Linux kernel version 6.4 and was fixed by rejecting the all-zeros address in the validation function. The issue can be triggered by unprivileged users in a new user and network namespace due to netns-scoped MDB operations.

References

Community reviews

Loading reviews…