CVE-2026-74290

Kernel-pointer disclosure via reversible address folding

Published Aug 15, 2026 · Updated Aug 15, 2026

Information disclosure in the Linux kernel cls_flow module allows local users to recover folded kernel pointer values through a tc classifier. The addr_fold() fallback XORs pointer halves for skb->sk, skb_dst(), or skb_nfct(), while attacker-chosen map parameters and class statistics expose the 32-bit result. Reaching the disclosure requires a local user to operate a map-mode tc classifier in a user or network namespace; the result reveals pointer-derived information but does not itself grant code execution.

CVSS severity5.5
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in the Linux kernel cls_flow module allows local users to recover folded kernel pointer values through a tc classifier. The addr_fold() fallback XORs pointer halves for skb->sk, skb_dst(), or skb_nfct(), while attacker-chosen map parameters and class statistics expose the 32-bit result. Reaching the disclosure requires a local user to operate a map-mode tc classifier in a user or network namespace; the result reveals pointer-derived information but does not itself grant code execution.

The record

CVE
CVE-2026-74290
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-201
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.6.25
  2. Affected versionversion=e5dfb815181fcb186d6080ac3a091eadff2d98fe <0a8b5b74f0e6b6b9ce453bcfa4baa502c4c7577a
  3. Affected versionversion=e5dfb815181fcb186d6080ac3a091eadff2d98fe <19f2ecf8ea564562c7e7a919cf38068dd9aa1c96
  4. Affected versionversion=e5dfb815181fcb186d6080ac3a091eadff2d98fe <3d054001860270748405a3f9270c5fa0bf7ffc19
  5. Affected versionversion=e5dfb815181fcb186d6080ac3a091eadff2d98fe <6151159618198675e01c391676e579738286c135
  6. Affected versionversion=e5dfb815181fcb186d6080ac3a091eadff2d98fe <f294fc71c4a0fa4964f6428a1b4e7929c1d83125
  7. Affected versionversion=e5dfb815181fcb186d6080ac3a091eadff2d98fe <fb31fbe51c233f3bf47021121f63d2e42cac2d08

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.25; version=e5dfb815181fcb186d6080ac3a091eadff2d98fe <0a8b5b74f0e6b6b9ce453bcfa4baa502c4c7577a; version=e5dfb815181fcb186d6080ac3a091eadff2d98fe <19f2ecf8ea564562c7e7a919cf38068dd9aa1c96; version=e5dfb815181fcb186d6080ac3a091eadff2d98fe <3d054001860270748405a3f9270c5fa0bf7ffc19; version=e5dfb815181fcb186d6080ac3a091eadff2d98fe <6151159618198675e01c391676e579738286c135; version=e5dfb815181fcb186d6080ac3a091eadff2d98fe <f294fc71c4a0fa4964f6428a1b4e7929c1d83125; version=e5dfb815181fcb186d6080ac3a091eadff2d98fe <fb31fbe51c233f3bf47021121f63d2e42cac2d08

Published CVSS scores

5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5Oracle LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
3.3Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-201Insertion of Sensitive Information Into Sent Data

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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