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 =====
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.]
Details
Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-63823
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-638230.12% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 3% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-63823 | coverage & exploitation status | NVD · CVE.org |
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