VulnerabilityPublished 2 Nov 2026

CVE-2026-99223: Linux kernel · keys: make keyring indexes independent of kernel addresses

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in e108b22999edbc6f431466baf6b2016c19b7ed31 : patch Linux kernel soon.

Data as of 2 Nov 2026, 16:31 UTC

Severity

High

Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD

Thin evidence

One scorer or none

Patch: Available – fixed in e108b22999edbc6f431466baf6b2016c19b7ed31, a113eba06bd1183c614d7994864d6e7054140cb9, 8451d4a4c43127c3b9fdf9fc9ff3fea5539a61f9 +5

Exploitation evidence

Disclosed: evidence found.
CVE published 2 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ b2a4df200d570b2c33a57e1ebfa5896e4bc81b69, < e108b22999edbc6f431466baf6b2016c19b7ed31	Fixed in e108b22999edbc6f431466baf6b2016c19b7ed31
LinuxLinux	Affected ≥ b2a4df200d570b2c33a57e1ebfa5896e4bc81b69, < a113eba06bd1183c614d7994864d6e7054140cb9	Fixed in a113eba06bd1183c614d7994864d6e7054140cb9
LinuxLinux	Affected ≥ b2a4df200d570b2c33a57e1ebfa5896e4bc81b69, < 8451d4a4c43127c3b9fdf9fc9ff3fea5539a61f9	Fixed in 8451d4a4c43127c3b9fdf9fc9ff3fea5539a61f9
LinuxLinux	Affected ≥ b2a4df200d570b2c33a57e1ebfa5896e4bc81b69, < 84f7c699f8d139f743c7dc11ef41d085690955bb	Fixed in 84f7c699f8d139f743c7dc11ef41d085690955bb
LinuxLinux	Affected ≥ b2a4df200d570b2c33a57e1ebfa5896e4bc81b69, < 61ac0585d9f4344d3dfb84b5edff1fee7d532897	Fixed in 61ac0585d9f4344d3dfb84b5edff1fee7d532897
LinuxLinux	Affected ≥ b2a4df200d570b2c33a57e1ebfa5896e4bc81b69, < 13fc051269d670810d9e314061b61c6dd06116a0	Fixed in 13fc051269d670810d9e314061b61c6dd06116a0

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AI-suggested

This vulnerability has been fixed in the Linux kernel. Users should update to a kernel version that includes the fix identified by the provided commit hashes. No additional mitigation is required once the kernel is updated.

Description

CVE-2026-99223 is a vulnerability in the Linux kernel's key management subsystem where keyring indexes leak kernel address information. This flaw allows an unprivileged user to predict the order of keys in a keyring and recover the kernel image address, potentially undermining Kernel Address Space Layout Randomization (KASLR). The issue has been fixed by removing kernel addresses from the index and using non-address-dependent identifiers with SipHash-based hashing.

Impact

An unprivileged user can exploit this vulnerability to recover the kernel image address by analyzing the order of keys in a keyring, effectively bypassing KASLR protections. This information disclosure could aid further kernel exploitation techniques that rely on knowing kernel memory layout.

Summary

The Linux kernel's key management system used keyring indexes that included kernel address information, specifically in the KEYCTL_READ operation which returns serial numbers in an associative-array traversal order. The first word of the index was a deterministic hash involving kernel pointers, allowing an unprivileged user to insert keys with known descriptions and predict their order for each possible KASLR slide, thereby leaking kernel image addresses. The fix replaces address-dependent ordering with a scheme that assigns each key type and domain a unique 64-bit ID and hashes these IDs with the description using a SipHash key, eliminating kernel address leakage. The patch maintains compatibility with existing key comparison, permissions, and userspace data formats.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 2 Nov 2026, 16:31 UTC

Technical details

References

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