CVE-2026-72323: Linux kernel · ipv4: igmp: Fix potential UAF in igmp_gq_start_timer()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 7.0.0-1013.13~24.04.1 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.7% chance of exploitation in 30 days – higher than 53% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-1013.13~24.04.1, 7.0.0-1017.17~24.04.1, 7.0.0-1016.16~24.04.1 +13
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 15 Aug 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
Upgrade to a fixed release listed under Affected software.
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 patch is available that fixes the vulnerability by changing reference counting logic to prevent use-after-free conditions. Users should apply the official Linux kernel updates that include this fix. The vendor advisory confirms multiple Linux kernel security fixes including this issue. No additional mitigation steps are required beyond applying the official patch.
Description
A use-after-free vulnerability in the Linux kernel's IPv4 IGMP implementation was fixed. The flaw arises from a race condition between device teardown and incoming IGMP query processing, leading to a kernel panic when a timer callback accesses freed memory. The issue is resolved by preventing reference acquisition on devices being destroyed. A similar IPv6 MLD issue is also addressed in a subsequent patch.
References
- nvd.nist.gov/vuln/detail/CVE-2026-72323 (opens in a new tab)
- git.kernel.org/stable/c/165258303357e54b75fc19b341ae2a2b7c9e3910 (opens in a new tab)
- git.kernel.org/stable/c/40a1e998cb266ed4cb529a0bb4fee2b0ba732702 (opens in a new tab)
- git.kernel.org/stable/c/75e984fe0cb9e7fbde0c8ee838c61ce8573d3ea3 (opens in a new tab)
- git.kernel.org/stable/c/7b19c0f81ed1fdaec6bc522569be367199a9edf3 (opens in a new tab)
- git.kernel.org/stable/c/8d4394ffa40508e0de72f464af351f6ca6a6cdc3 (opens in a new tab)
- ubuntu.com/security/CVE-2026-72323 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-72323 (opens in a new tab)
- git.kernel.org/linus/7b19c0f81ed1fdaec6bc522569be367199a9edf3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8781-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)