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Response snapshot Nov 2, 2026, 17:11 UTC

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VulnerabilityCVE-2026-99236

Linux kernel: tracing: Reject incomplete event filter expressions

In the Linux kernel, the following vulnerability has been resolved: tracing: Reject incomplete event filter expressions A non-empty expression normally finishes in predicate_parse()'s inner loop, which resolves the pending logical operators before jumping to finalization.

At a glance

Exploited
Not known
Severity
7.8 High (CVSS 3.1)
Chance of exploitation
Not estimated
Sources
1 source

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-99236 (opens a new tab)

What happened

In the Linux kernel, the following vulnerability has been resolved:

tracing: Reject incomplete event filter expressions

A non-empty expression normally finishes in predicate_parse()'s inner loop, which resolves the pending logical operators before jumping to finalization. If the input ends after an operator, possibly followed by unary '!' tokens, the outer loop instead falls through with unresolved operator state.

For example, "common_pid == 1 || common_pid == 2 &&" leaves prog[0].target equal to -1. The second pass then reads prog[-1] before the forward-jump check can reject it. Depending on adjacent slab contents, it can also copy an out-of-bounds word into a branch target that passes the forward-only check. A self-targeted perf tracepoint counting event can reach this path through PERF_EVENT_IOC_SET_FILTER.

Continue reading

Reject the outer-loop fallthrough when a predicate has already been parsed. This ensures that non-empty expressions only reach finalization after the inner loop has resolved their operators. Keep the existing no-filter error for input that has no predicates. Add a regression test for trailing logical operators and unary negations.

Scores and how they were measured

CVSS base severity

7.8

Version 3.1As of

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

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    NVD CVE-2026-99236 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  3. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, November 2). Linux kernel: tracing: Reject incomplete event filter expressions (CVE-2026-99236). https://kevwire.com/record/CVE-2026-99236

MLA

"Linux kernel: tracing: Reject incomplete event filter expressions (CVE-2026-99236)." KEVWire, 2 Nov. 2026, kevwire.com/record/CVE-2026-99236.

Chicago

KEVWire. "Linux kernel: tracing: Reject incomplete event filter expressions (CVE-2026-99236)." Last modified November 2, 2026. https://kevwire.com/record/CVE-2026-99236.

Evidence summary (plain text)

Linux kernel: tracing: Reject incomplete event filter expressions (Nov 2, 2026).
In the Linux kernel, the following vulnerability has been resolved:

tracing: Reject incomplete event filter expressions

A non-empty expression normally finishes in predicate_parse()'s inner
loop, which resolves the pending logical operators before jumping to
finalization. If the input ends after an operator, possibly followed by
unary '!' tokens, the outer loop instead falls through with unresolved
operator state.

For example, "common_pid == 1 || common_pid == 2 &&" leaves
prog[0].target equal to -1. The second pass then reads prog[-1] before
the forward-jump check can reject it.
CVSS 7.8 (version 3.1; evidence as of Nov 2, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-99236).
Sources:
NVD CVE-2026-99236: https://nvd.nist.gov/vuln/detail/CVE-2026-99236
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-02T15:36:06.356Z&lastModEndDate=2026-11-02T17:10:56.063Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-02T15:01:12.608Z&lastModEndDate=2026-11-02T16:35:57.586Z&resultsPerPage=500&startIndex=500
Record ID: CVE-2026-99236.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Nov 2, 2026, 17:10 UTC. Ingestion is not an independent editorial investigation.

NVD status: Received. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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