CVE-2026-72052: Linux kernel · net: ip6_gre: require CAP_NET_ADMIN in the device netns for changelink
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.8 High · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +42
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/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 corrects the capability checks to require CAP_NET_ADMIN in both relevant network namespaces before allowing tunnel link changes. Users should apply the official Linux kernel updates for the affected versions as provided by their distribution vendors. No additional mitigation is required beyond applying the patch.
Description
A vulnerability in the Linux kernel's ip6_gre module allowed insufficient privilege checks when changing tunnel links across network namespaces. The issue was that CAP_NET_ADMIN capability was only checked in the device's original network namespace, not the tunnel's network namespace, enabling a caller privileged in one namespace but not the other to rewrite tunnels improperly. This flaw has been resolved by gating the operations on a capability check that covers both namespaces.
References
- nvd.nist.gov/vuln/detail/CVE-2026-72052 (opens in a new tab)
- git.kernel.org/stable/c/03d8843b143ebbbfaf48511922abc6e886575a61 (opens in a new tab)
- git.kernel.org/stable/c/0caa9f348f8b5356900de77b0bb89a697c4aff20 (opens in a new tab)
- git.kernel.org/stable/c/129f8939e5af683cec3a1a5edcb40a64636ad81e (opens in a new tab)
- git.kernel.org/stable/c/1d4d8ee002083ca4ead5353662bf8362428af57f (opens in a new tab)
- git.kernel.org/stable/c/220162c9fedbe992da70d70f50a10da4f45f914c (opens in a new tab)
- git.kernel.org/stable/c/c38c8b0db3c65b597e7ece317b6cb59de3d15e69 (opens in a new tab)
- git.kernel.org/stable/c/e3724dedf57761c6de52f4d604ec74f66fd61611 (opens in a new tab)
- git.kernel.org/stable/c/f00a50876d2818bd6dc86fa98b3ef360884c53c8 (opens in a new tab)
- ubuntu.com/security/CVE-2026-72052 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-72052 (opens in a new tab)
- git.kernel.org/linus/f00a50876d2818bd6dc86fa98b3ef360884c53c8 (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (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-8886-1 (opens in a new tab)