ipv6: flowlabel: cap duplicate leases per socket
Key facts
- Attack vector
- —
- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
- —
- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 7 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: ipv6: flowlabel: cap duplicate leases per socket ipv6_flowlabel_get() allocates an ipv6_fl_socklist entry for every successful GET. The recheck path for a compatible existing flowlabel links another lease without applying any lease admission check. Repeated GET requests for one shareable label can therefore grow a socket's lease list without bound. Reject a new unprivileged lease once the socket already holds FL_MAX_PER_SOCK leases. Check this on the shared recheck path so reuse of a globally interned label, including the fl_intern() collision path, is covered as well. New-label admission remains under the existing mem_check() policy. Use capable(CAP_NET_ADMIN) rather than ns_capable(), matching mem_check(). An unprivileged user must not bypass the cap by creating a user namespace and a netns where they have CAP_NET_ADMIN, which would still consume host memory. Check the capability only when the socket reaches the limit, so successful unprivileged GET requests below the cap do not generate a capability audit. Do the admission check before updating linger and expires so a rejected GET does not refresh the shared label, matching the existing socket-list allocation failure path.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.1.191, 6.6.160, 6.12.112, 6.18.53, 7.2.7, 7.3
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-97597
- 2026-10-03 Alias added: GHSA-7x5f-23mf-qfp3
- 2026-10-03 Fix available: Linux/[email protected], Linux/Linux@6d917992c22b6029fc2dc1bd464b7f6709357161 · CNA
- 2026-10-03 1 new reference · CNA
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-21 Fix available: Linux/Linux@0159f716d8adbe85951cdf008d0afe27d874eaa6, Linux/[email protected] · CNA
- 2026-10-21 1 new reference · CNA
- 2026-10-30 Fix available: Linux/Linux@42abef116bb2265eeccae55a0dc91a9f1546f74c, Linux/[email protected] · CNA
- 2026-10-30 1 new reference · CNA
- 2026-11-07 Affected versions changed · Red Hat
References
Other 6
- https://git.kernel.org/stable/c/42abef116bb2265eeccae55a0dc91a9f1546f74c
- https://git.kernel.org/stable/c/0159f716d8adbe85951cdf008d0afe27d874eaa6
- https://git.kernel.org/stable/c/6d917992c22b6029fc2dc1bd464b7f6709357161
- https://git.kernel.org/stable/c/2f1a6dd5c80ceb902f50449efe899f29cd7918e3
- https://git.kernel.org/stable/c/467467bf4209f9f8add0c648bae763f92a0224c3
- https://git.kernel.org/stable/c/8d6cd188508513503805c156165de38e4e4a8615
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Sources
- CVE-2026-97597 · CVE Program
- CVE-2026-97597 · NVD
- FIRST EPSS
- GHSA-7x5f-23mf-qfp3 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-97597 · Red Hat security data · CC BY 4.0
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