VulnerabilityPublished 28 Oct 2026

CVE-2026-99159: Linux kernel · ring-buffer: Fix the sub-buffer array base in rb_meta_subbuf_idx()

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in 25132363c723afc39aace8b098f547ab4a0ea759 : update Linux kernel when convenient.

Data as of 28 Oct 2026, 10:58 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

Patch: Available – fixed in 25132363c723afc39aace8b098f547ab4a0ea759, 7469b3585ef5f65840d467d2caa811a9098c84b9, 2f1248b728b56d583ea454fedf239550c49f7b18

Exploitation evidence

Disclosed: evidence found.
CVE published 28 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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 Linux kernel to 25132363c723afc39aace8b098f547ab4a0ea759, 7469b3585ef5f65840d467d2caa811a9098c84b9 or 2f1248b728b56d583ea454fedf239550c49f7b18.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ b14d032973d4e6c36e025e96ea3437de53d072d9, < 25132363c723afc39aace8b098f547ab4a0ea759	Fixed in 25132363c723afc39aace8b098f547ab4a0ea759
LinuxLinux	Affected ≥ b14d032973d4e6c36e025e96ea3437de53d072d9, < 7469b3585ef5f65840d467d2caa811a9098c84b9	Fixed in 7469b3585ef5f65840d467d2caa811a9098c84b9
LinuxLinux	Affected ≥ b14d032973d4e6c36e025e96ea3437de53d072d9, < 2f1248b728b56d583ea454fedf239550c49f7b18	Fixed in 2f1248b728b56d583ea454fedf239550c49f7b18
LinuxLinux	Affected =6.12	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Fix the sub-buffer array base in rb_meta_subbuf_idx() On a persistent ring buffer, rb_meta_subbuf_idx() can return an index one sub-buffer too high. rb_setup_ids_meta_page() then fills subbuf_ids[] shifted by one and leaves subbuf_ids[0] NULL, which __rb_map_vma() dereferences when userspace maps trace_pipe_raw. rb_update_meta_reader() writes two such indices into meta->buffers[], which rb_cpu_meta_valid() would reject on the next boot, discarding the previous boot's trace. A CPU's sub-buffer array starts after its meta header and the nr_subbufs integers that follow, aligned up to a sub-buffer. rb_meta_subbuf_idx() inverts that calculation but skips only the integers, not the header, so its base is one sub-buffer low whenever the omitted header size crosses the alignment boundary. Invert the calculation with rb_subbufs_from_meta() rather than repeating it. rb_range_buffer() maps an index back to an address through the same helper, so the two directions can no longer disagree.

References

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