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CVE-2026-63823

HIGHCVSS 7.8/10EPSS 0.12%

Last modified

CVE-2026-63823 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: keys: Pin request_key_auth payload in instantiate paths A: request_key() B: KEYCTL_INSTANTIATE_IOV ================ ========================= create auth key store rka in auth key wait for helper get auth key load rka from auth key copy user payload sleep on #PF helper completed detach and free rka destroy auth key wake up use rka->target_key **USE-AFTER-FREE** Give request_key_auth payloads a refcount. Take a payload reference while authkey->sem stabilizes the payload and revocation state. EPSS estimates a 0.12% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: keys: Pin request_key_auth payload in instantiate paths A: request_key() B: KEYCTL_INSTANTIATE_IOV ================ ========================= create auth key store rka in auth key wait for helper get auth key load rka from auth key copy user payload sleep on #PF helper completed detach and free rka destroy auth key wake up use rka->target_key **USE-AFTER-FREE** Give request_key_auth payloads a refcount. Take a payload reference while authkey->sem stabilizes the payload and revocation state. Hold that reference across the instantiate and reject paths. Drop the auth key owning reference from revoke and destroy. [jarkko: Replaced the first two paragraphs of text with an actual concurrency scenario.]

Metrics

CVSS 3.1
7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
0.12%

2.5th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= b5f545c880a2a47947ba2118b2509644ab7a2969, < d8274181b0f28d450b42489723a5ba81042158d7; >= b5f545c880a2a47947ba2118b2509644ab7a2969, < 4982bfabce6b33b3c9eddb4fb900fe5568b7cf91; >= b5f545c880a2a47947ba2118b2509644ab7a2969, < 708709c65a1832a99b0eef8ae46e343ddaca3d06; >= b5f545c880a2a47947ba2118b2509644ab7a2969, < 35ab4db86774d82389e4b9559e26ab7f68d8e395; >= b5f545c880a2a47947ba2118b2509644ab7a2969, < f9b68632ac93cc742f2e411021c4dbfe452ea0c2; >= b5f545c880a2a47947ba2118b2509644ab7a2969, < 7216ce8cb12fee44e309503955bb83806b106129; >= b5f545c880a2a47947ba2118b2509644ab7a2969, < 83c0a1cb296d955d5f4d1f0bd8a769ba8ed8c29f; >= b5f545c880a2a47947ba2118b2509644ab7a2969, < fd15b457a86939c38aa12116adabd8ff686c5e51
LinuxLinux2.6.16

References

Timeline

Published
Last Modified
Status
Awaiting Analysis

Frequently Asked Questions

What is CVE-2026-63823?
In the Linux kernel, the following vulnerability has been resolved: keys: Pin request_key_auth payload in instantiate paths A: request_key() B: KEYCTL_INSTANTIATE_IOV ================ ========================= create auth key store rka in auth key wait for helper get auth key load rka from auth key copy user payload sleep on #PF helper completed detach and free rka destroy auth key wake up use rka->target_key **USE-AFTER-FREE** Give request_key_auth payloads a refcount. Take a payload reference while authkey->sem stabilizes the payload and revocation state. Hold that reference across the instantiate and reject paths. Drop the auth key owning reference from revoke and destroy. [jarkko: Replaced the first two paragraphs of text with an actual concurrency scenario.]
How severe is CVE-2026-63823?
CVE-2026-63823 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.12% probability of exploitation in the next 30 days.
How do I fix CVE-2026-63823?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST