CVE Catalog

CVE-2026-63823

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.12%

3th percentile - higher than 3% of all known CVEs

Summary

A use-after-free vulnerability was found in the Linux kernel's key management subsystem. A race condition between request_key() and KEYCTL_INSTANTIATE_IOV can cause use of freed request_key_auth payload memory.

Risk Assessment

An attacker could exploit this vulnerability for privilege escalation or information disclosure, compromising system confidentiality and integrity.

Recommendation

Apply the Linux kernel patch that adds reference counting for request_key_auth payloads and proper locking in instantiate and reject paths.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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.]

Vulnerability data from NVD (NIST) · CISA KEV · EPSS