CVE-2026-89487: Linux kernel · openvswitch: only skb_tx_error() a packet we are about to drop
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 13:47 UTC
- 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.
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 11 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
No explicit vendor advisory or patch link is provided in the input data. Until a fix is applied, avoid running vulnerable kernel versions or restrict unprivileged user access to affected networking features. Monitor vendor channels for official patches addressing this issue.
Description
A vulnerability in the Linux kernel's Open vSwitch (openvswitch) component was resolved that involved improper handling of packet skb flags during error processing. The issue caused the stripping of the SKBFL_SHARED_FRAG flag on a live socket buffer (skb) that was still being forwarded, leading to an unprivileged write to page-cache memory. This was due to skb_tx_error() being called on a packet that was not yet dropped, affecting in-place decryption of ESP-in-UDP packets and enabling a local page-cache write primitive. The fix moves the skb_tx_error() call to the appropriate flow-miss drop path to prevent this unsafe modification.
References
- nvd.nist.gov/vuln/detail/CVE-2026-89487 (opens in a new tab)
- git.kernel.org/stable/c/0dbc2398fca3bb33eda963849f865ddb1b3aa05e (opens in a new tab)
- git.kernel.org/stable/c/5d85eef222cfd28e73deed7402c100229e8b9e6e (opens in a new tab)
- git.kernel.org/stable/c/6767d70cf46f65807a6a4c4406a518e6c12e36ae (opens in a new tab)
- git.kernel.org/stable/c/e41a59fc056f63a7a1f42788913c53cc48d744aa (opens in a new tab)
- ubuntu.com/security/CVE-2026-89487 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89487 (opens in a new tab)
- git.kernel.org/linus/0dbc2398fca3bb33eda963849f865ddb1b3aa05e (opens in a new tab)
- msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-89487.json (opens in a new tab)
- support.microsoft.com/lifecycle (opens in a new tab)
- first.org/cvss (opens in a new tab)