CVE-2026-72321: Linux kernel · ipv4: igmp: Fix potential memory leaks in igmp_mod_timer() and igmp_stop_timer()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.7 Medium · fixed in 7.0.0-1014.14~24.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-1014.14~24.04.1, 7.0.0-1017.17~24.04.1, 7.0.0-1016.16~24.04.1 +11
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation 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 to fix this vulnerability by updating the Linux kernel to a version that includes the corrected reference count handling in the IGMP subsystem. Users should apply the official kernel updates from their distribution vendors. No additional mitigation steps are indicated or required beyond applying the patch.
Description
A vulnerability in the Linux kernel's IPv4 IGMP implementation could cause potential memory leaks due to improper reference count handling when timers are deleted or stopped. The flaw occurs when the reference count of a multicast list entry is decremented incorrectly, leading to leaked memory structures. This issue has been resolved by changing the reference count decrement method to properly free the affected structures after releasing a spinlock.
References
- nvd.nist.gov/vuln/detail/CVE-2026-72321 (opens in a new tab)
- git.kernel.org/stable/c/3546deaa0c30a14c7cdb5dc8f2432cb428f0cd36 (opens in a new tab)
- git.kernel.org/stable/c/95128dc74425ec19ed4f2077ccc651e791ff4b75 (opens in a new tab)
- git.kernel.org/stable/c/f60ec3058a85447008b88b762c859d336163acb3 (opens in a new tab)
- ubuntu.com/security/CVE-2026-72321 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-72321 (opens in a new tab)
- git.kernel.org/linus/3546deaa0c30a14c7cdb5dc8f2432cb428f0cd36 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-3 (opens in a new tab)