net/sched: cls_flow: Dont expose folded kernel pointers
Key facts
- Attack vector
- —
- Privileges required
- —
- User interaction
- —
- Attack complexity
- —
- Impact type
- —
- Confidentiality · integrity · availability
- —
- Fix status
- Partial Red Hat: 5 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: net/sched: cls_flow: Dont expose folded kernel pointers The flow classifier falls back to addr_fold() for fields that are missing from packet headers. In map mode, userspace controls mask, xor, rshift, addend and divisor, and can observe the resulting classid through class statistics. This allows a tc classifier in a user/network namespace to recover the 32-bit folded value of skb->sk, skb_dst() or skb_nfct(). Align with standard kernel practices for pointer hashing and replace the XOR folding with a keyed siphash (which is cryptographically secure)
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2
Vendor assessments
Red Hat
Red Hat rating: Moderate. 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 |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-74290
- 2026-10-03 Alias added: GHSA-wfqw-582v-82vh
- 2026-11-06 CVSS score changed · Red Hat
- 2026-11-06 CISA SSVC decision points changed
References
Other 6
- https://git.kernel.org/stable/c/19f2ecf8ea564562c7e7a919cf38068dd9aa1c96
- https://git.kernel.org/stable/c/3d054001860270748405a3f9270c5fa0bf7ffc19
- https://git.kernel.org/stable/c/fb31fbe51c233f3bf47021121f63d2e42cac2d08
- https://git.kernel.org/stable/c/0a8b5b74f0e6b6b9ce453bcfa4baa502c4c7577a
- https://git.kernel.org/stable/c/6151159618198675e01c391676e579738286c135
- https://git.kernel.org/stable/c/f294fc71c4a0fa4964f6428a1b4e7929c1d83125
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Sources
- CVE-2026-74290 · CVE Program
- CVE-2026-74290 · NVD
- FIRST EPSS
- GHSA-wfqw-582v-82vh · GitHub Advisory Database · CC BY 4.0
- CVE-2026-74290 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences