CVE-2026-89789: Linux kernel · gtp: add synchronize_net() in gtp_newlink() error path to prevent use-after-free
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% 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 16 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 adds synchronize_net() calls in the gtp_newlink() error path to prevent use-after-free conditions. Users should apply the official patches provided for the affected Linux kernel versions to remediate this vulnerability.
Description
A use-after-free vulnerability in the Linux kernel's GTP module was resolved by adding synchronize_net() in the gtp_newlink() error path. The issue involved freeing tid_hash and addr_hash without waiting for an RCU grace period, allowing concurrent access to freed memory. This could lead to memory corruption and potentially impact confidentiality, integrity, and availability.
References
- ubuntu.com/security/CVE-2026-89789 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89789 (opens in a new tab)
- git.kernel.org/linus/d989e22ae9802c52c56ad4284d0caf26696cf6ae (opens in a new tab)
- git.kernel.org/stable/c/3ca3da5c305caa873ddb81e8c6b118143f6dd3d1 (opens in a new tab)
- git.kernel.org/stable/c/6f815c2fb6ab20385f81c353cdad0ea3b88132af (opens in a new tab)
- git.kernel.org/stable/c/7677eb2cbf2cc7446de474c01a6b06277c0051e5 (opens in a new tab)
- git.kernel.org/stable/c/8d85498016a5bb56339734a14c276209fa65bafc (opens in a new tab)
- git.kernel.org/stable/c/d989e22ae9802c52c56ad4284d0caf26696cf6ae (opens in a new tab)
- git.kernel.org/stable/c/e3b9aa0773abd5d4ed90be41ce5306c146d5b09e (opens in a new tab)
- git.kernel.org/stable/c/fcafb2b1430824bae4258c01a439ec97ca0c6973 (opens in a new tab)
- git.kernel.org/stable/c/fd8396cfecbd904468c71362f08aaa25f96d5337 (opens in a new tab)
- msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-89789.json (opens in a new tab)
- support.microsoft.com/lifecycle (opens in a new tab)
- first.org/cvss (opens in a new tab)