CVE-2026-74433Network attack vector

Stale memory access via freed challenge header

Published Aug 15, 2026 · Updated Aug 15, 2026

Use-after-free in Linux kernel RxRPC 6.16 and later allows remote attackers to trigger stale memory access through an RxGK challenge. rxgk_issue_challenge() frees the page holding the transmitted challenge before trace_rxrpc_tx_packet() reads its whdr pointer. Network reachability to an RxGK-enabled RxRPC service is required; public upstream material identifies no demonstrated post-trigger consequence.

CVSS severity9.8
Critical
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux kernel RxRPC 6.16 and later allows remote attackers to trigger stale memory access through an RxGK challenge. rxgk_issue_challenge() frees the page holding the transmitted challenge before trace_rxrpc_tx_packet() reads its whdr pointer. Network reachability to an RxGK-enabled RxRPC service is required; public upstream material identifies no demonstrated post-trigger consequence.

The record

CVE
CVE-2026-74433
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
network
Privileges
unauthenticated

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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=6.16
  2. Affected versionversion=9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a <107a4cb0d47e735830f852d83970d5c81f8e1e08
  3. Affected versionversion=9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a <83bb0ed050e2ad9453d8ef50e4d6e624eac6eed8
  4. Affected versionversion=9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a <844b8525ce503405c462ad67f750bec648720397

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.16; version=9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a <107a4cb0d47e735830f852d83970d5c81f8e1e08; version=9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a <83bb0ed050e2ad9453d8ef50e4d6e624eac6eed8; version=9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a <844b8525ce503405c462ad67f750bec648720397

Published CVSS scores

9.8Canonical UbuntuCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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