CVE-2026-74290: Linux kernel · net/sched: cls_flow: Dont expose folded kernel pointers
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in fb31fbe51c233f3bf47021121f63d2e42cac2d08 : update Linux kernel when convenient.
Data as of 6 Nov 2026, 18:10 UTC
Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD
Thin evidence
One scorer or none- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-11-06.
- Patch
- Available – fixed in fb31fbe51c233f3bf47021121f63d2e42cac2d08, f294fc71c4a0fa4964f6428a1b4e7929c1d83125, 6151159618198675e01c391676e579738286c135 +3
Exploitation evidence
Disclosed: evidence found.
CVE published 15 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 6 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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AI-suggested
A fix is available and has been applied in multiple Linux kernel commits. Users should update their Linux kernel to a version that includes these fixes to mitigate the vulnerability. No additional mitigation steps are indicated by the vendor advisory.
Description
A vulnerability in the Linux kernel's network scheduler flow classifier (cls_flow) allowed exposure of folded kernel pointers. The issue arose because the flow classifier used addr_fold() with user-controlled parameters to fold kernel pointers, enabling recovery of 32-bit folded values of sensitive kernel pointers such as skb->sk, skb_dst(), or skb_nfct(). This could potentially leak kernel pointer information. The vulnerability has been fixed by replacing the insecure XOR folding with a cryptographically secure keyed siphash, aligning with standard kernel pointer hashing practices.
References
- git.kernel.org/stable/c/19f2ecf8ea564562c7e7a919cf38068dd9aa1c96 (opens in a new tab)
- git.kernel.org/stable/c/3d054001860270748405a3f9270c5fa0bf7ffc19 (opens in a new tab)
- git.kernel.org/stable/c/fb31fbe51c233f3bf47021121f63d2e42cac2d08 (opens in a new tab)
- git.kernel.org/stable/c/0a8b5b74f0e6b6b9ce453bcfa4baa502c4c7577a (opens in a new tab)
- git.kernel.org/stable/c/6151159618198675e01c391676e579738286c135 (opens in a new tab)
- git.kernel.org/stable/c/f294fc71c4a0fa4964f6428a1b4e7929c1d83125 (opens in a new tab)