CVE-2026-97598: Linux kernel · ipv4: fib: bound automatic table ID allocation
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 12:55 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 25 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 bounds the automatic IPv4 routing table ID allocation to 4096, preventing unbounded RTNL lock holds. Systems should apply the patch to affected Linux kernel versions. Since the automatic allocation path is unused by common tools and IPv4-only, the impact is limited. No additional mitigation is required beyond applying the official fix.
Description
A vulnerability in the Linux kernel's IPv4 routing table ID allocation was resolved by bounding the automatic table ID allocation to 4096. Previously, the function fib_empty_table() probed every table ID from 1 up to RT_TABLE_MAX (0xFFFFFFFF) to find a free ID, causing potentially unbounded RTNL lock hold times. The fix limits the search to 4096, causing rule addition to fail with ENOBUFS if the range is exhausted. This automatic allocation path is IPv4-only, legacy, undocumented, and unused by major tools like NetworkManager and systemd.
References
- ubuntu.com/security/CVE-2026-97598 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-97598 (opens in a new tab)
- git.kernel.org/stable/c/bc8d01d856db106f284b19961af6112e10c3e3b4 (opens in a new tab)
- git.kernel.org/stable/c/fe9a906d2bff2d2707bafd6353b5e032a42aeb35 (opens in a new tab)
- git.kernel.org/stable/c/2c29c053a6627dc4f12fcfe6b4860bcd9e5d7503 (opens in a new tab)
- git.kernel.org/stable/c/efdfb1e27a3328085b79540dfe781d537b576ea1 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-97598 (opens in a new tab)
- git.kernel.org/stable/c/125890702ef4417cd0ffac2e448c0cd4fbf0ac45 (opens in a new tab)
- git.kernel.org/stable/c/3080f9e653d8c057d5652db5ced8137f81b3fcbd (opens in a new tab)
- git.kernel.org/stable/c/999bc00588cb305ab25065e8a8ac31da7465301c (opens in a new tab)
- git.kernel.org/stable/c/f1f2da33eaab54b4d5cdea6d70befb2e2fb49cb6 (opens in a new tab)