CVE-2026-98625: Linux kernel · netfilter: flowtable: publish HW_DEAD after worker is done
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.3 High.
Data as of 28 Oct 2026, 01:28 UTC
CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 18 Oct 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.
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: flowtable: publish HW_DEAD after worker is done flow_offload_work_del() sets NF_FLOW_HW_DEAD before the work handler clears NF_FLOW_HW_PENDING. Once a flow is both HW_DYING and HW_DEAD, a concurrent garbage collection pass can remove it and schedule it for RCU freeing. The offload worker holds neither an RCU read lock nor a reference to the flow. If it is preempted after publishing HW_DEAD, the RCU callback can free the flow before the worker resumes and clears HW_PENDING, resulting in a use-after-free. Move HW_DEAD publication to the common worker epilogue after the pending bit is cleared, making it the final flow access by destroy work. Order all preceding flow accesses before publishing the bit that allows garbage collection to free the object.
References
- ubuntu.com/security/CVE-2026-98625 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98625 (opens in a new tab)
- git.kernel.org/stable/c/00e452a7ca9fda135ea3d04a11128d5088e354a8 (opens in a new tab)
- git.kernel.org/stable/c/f92e8f39726ba68a7c42c6b7566be687c8161579 (opens in a new tab)
- git.kernel.org/stable/c/b0ef9450e93f2adeb77593db14c2ac7c6c8f5060 (opens in a new tab)
- git.kernel.org/stable/c/e20701843032c438f879066a77ea85e361c6b999 (opens in a new tab)
- git.kernel.org/stable/c/f26652e99f519e6bd34f8a9b48fbb33c603585f2 (opens in a new tab)
- git.kernel.org/stable/c/56f39c7d139bb76072efe2fb3dcafc13ba915ad8 (opens in a new tab)
- git.kernel.org/stable/c/d644b23afe1ef509c9961a6d84a093c2587edf02 (opens in a new tab)
- git.kernel.org/stable/c/b4f0f05dfbe836a171bff261f17d098a4d5461ea (opens in a new tab)