# CVE-2026-99236: tracing: Reject incomplete event filter expressions

CVE-2026-99236 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-99236, released November 3, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-99236
- Priority: High
- CVSS: 7.8 (Moderate)
- EPSS: 0.0013
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Nov 2, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-99236

## Description

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.  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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 13.5 (trixie) | 6.12.115-1 | [DEBIAN-CVE-2026-99236](https://patchblox.com/security/data/fix/linux/debian-cve-2026-99236.md) | Nov 3, 2026 |
| Linux | linux Debian 14 | 7.2.14-1 | [DEBIAN-CVE-2026-99236](https://patchblox.com/security/data/fix/linux/debian-cve-2026-99236.md) | Nov 3, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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