CVE-2025-40109

Kernel crash via RNG null pointer dereference

Published Nov 9, 2025 · Updated Nov 9, 2025

Null-pointer dereference in the Linux kernel Crypto API allows local users to crash the system through a crafted AF_ALG socket. The rng_setentropy path calls the selected rng_alg set_ent callback without ensuring that non-DRBG algorithms such as jent_alg implement it. The trigger requires CONFIG_CRYPTO_USER_API_RNG_CAVP and an AF_ALG socket bound to such an RNG before ALG_SET_DRBG_ENTROPY is set.

CVSS severityUnavailable
Unscored
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Null-pointer dereference in the Linux kernel Crypto API allows local users to crash the system through a crafted AF_ALG socket. The rng_setentropy path calls the selected rng_alg set_ent callback without ensuring that non-DRBG algorithms such as jent_alg implement it. The trigger requires CONFIG_CRYPTO_USER_API_RNG_CAVP and an AF_ALG socket bound to such an RNG before ALG_SET_DRBG_ENTROPY is set.

The record

CVE
CVE-2025-40109
Published
Nov 9, 2025
Updated
Nov 9, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Nov 9, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 9, 2025Record 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=5.10
  2. Affected versionversion=77ebdabe8de7c02f43c6de3357f79ff96f9f0579 <15d6f42da1bb527629d8e1067b1302d58dec9166
  3. Affected versionversion=77ebdabe8de7c02f43c6de3357f79ff96f9f0579 <17acbcd44fe8dc17dc1072375e76df2d52da6ac8
  4. Affected versionversion=77ebdabe8de7c02f43c6de3357f79ff96f9f0579 <915cb75983bc5e8b80f8a2f25a4af463f7b18c14
  5. Affected versionversion=77ebdabe8de7c02f43c6de3357f79ff96f9f0579 <ab172f4f42626549b02bada05f09e3f2b0cc26ec
  6. Affected versionversion=77ebdabe8de7c02f43c6de3357f79ff96f9f0579 <bd903c25b652c331831226cdf56c8179d18e43f4
  7. Affected versionversion=77ebdabe8de7c02f43c6de3357f79ff96f9f0579 <c0d36727bf39bb16ef0a67ed608e279535ebf0da
  8. Affected versionversion=77ebdabe8de7c02f43c6de3357f79ff96f9f0579 <c5c703b50e91dd4748769f4c5ab50d9ad60be370
  9. Affected versionversion=77ebdabe8de7c02f43c6de3357f79ff96f9f0579 <e247a7d138e514a40edda7c4d72c8bd49bb2cad3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=5.10; version=77ebdabe8de7c02f43c6de3357f79ff96f9f0579 <15d6f42da1bb527629d8e1067b1302d58dec9166; version=77ebdabe8de7c02f43c6de3357f79ff96f9f0579 <17acbcd44fe8dc17dc1072375e76df2d52da6ac8; version=77ebdabe8de7c02f43c6de3357f79ff96f9f0579 <915cb75983bc5e8b80f8a2f25a4af463f7b18c14; version=77ebdabe8de7c02f43c6de3357f79ff96f9f0579 <ab172f4f42626549b02bada05f09e3f2b0cc26ec; version=77ebdabe8de7c02f43c6de3357f79ff96f9f0579 <bd903c25b652c331831226cdf56c8179d18e43f4; version=77ebdabe8de7c02f43c6de3357f79ff96f9f0579 <c0d36727bf39bb16ef0a67ed608e279535ebf0da; version=77ebdabe8de7c02f43c6de3357f79ff96f9f0579 <c5c703b50e91dd4748769f4c5ab50d9ad60be370; version=77ebdabe8de7c02f43c6de3357f79ff96f9f0579 <e247a7d138e514a40edda7c4d72c8bd49bb2cad3

Published CVSS scores

No CVSS assessment is available in this record.

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)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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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