Linux Kernel up to 6.18.38/7.1.3 loongson-rng wait_for_completion_interruptible use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.5$5k-$25k2.40

Summaryinfo

A vulnerability described as very critical has been identified in Linux Kernel up to 6.18.38/7.1.3. Affected by this vulnerability is the function wait_for_completion_interruptible of the component loongson-rng. Such manipulation leads to use after free. This vulnerability is listed as CVE-2026-64311. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.38/7.1.3 and classified as very critical. Affected by this issue is the function wait_for_completion_interruptible of the component loongson-rng. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: crypto: loongson - Remove broken and unused loongson-rng The loongson-rng rng_alg has several vulnerabilities, including not providing forward security, and a use-after-free bug due to the use of wait_for_completion_interruptible(). Meanwhile, the rng_alg framework doesn't really have any purpose in the first place other than to access the software algorithms crypto/drbg.c and crypto/jitterentropy.c. Hardware-specific rng_algs have no in-kernel user, and unlike hwrng there's no feed into the actual Linux RNG. As such, there's really no point to this code. There are of course other rng_alg drivers that are similarly unused, but they're similarly in the process of being phased out, e.g. https://lore.kernel.org/r/[email protected] and https://lore.kernel.org/r/[email protected] Given that, there's no point in fixing forward these vulnerabilities, and it makes much more sense to simply roll back the addition of this driver. If this platform provides TRNG (not PRNG) functionality, it could make sense to add a hwrng driver, but it would be quite different.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-64311 since 07/19/2026. The exploitation is known to be easy. The attack may be launched remotely. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 07/25/2026).

Upgrading to version 6.18.39, 7.1.4 or 7.2-rc1 eliminates this vulnerability. Applying the patch 037ec8353711c79353b12d5634e0c9ff363a9efa/43de8b9f01b7dd2f6ca5360c6bf2f203c02288dc/af3d1bb9a09daf928fc3f173689fb7904d6a6d4f is able to eliminate this problem.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.18.39/7.1.4/7.2-rc1
Patch: 037ec8353711c79353b12d5634e0c9ff363a9efa/43de8b9f01b7dd2f6ca5360c6bf2f203c02288dc/af3d1bb9a09daf928fc3f173689fb7904d6a6d4f

Timelineinfo

07/19/2026 CVE reserved
07/25/2026 +6 days Advisory disclosed
07/25/2026 +0 days VulDB entry created
07/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-64311 (🔒)
GCVE (CVE): GCVE-0-2026-64311
GCVE (VulDB): GCVE-100-383108

Entryinfo

Created: 07/25/2026 14:48
Changes: 07/25/2026 14:48 (59)
Complete: 🔍
Cache ID: 216::103

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