CVE Catalog

CVE-2026-99236

HighCVSS 7.8
Published: Translated: NVD NIST

Summary

A Linux kernel tracing vulnerability: incomplete event filter expressions (e.g., ending with a logical operator) left unresolved operator state, causing an out-of-bounds read (prog[-1]) or copying an out-of-bounds word into a branch target. This could be reached via PERF_EVENT_IOC_SET_FILTER on a self-targeted perf tracepoint counting event.

Risk Assessment

A local attacker could trigger an out-of-bounds read or write in the kernel, potentially causing a system crash or privilege escalation. Exploitation requires the ability to set perf event filters.

Recommendation

Update the Linux kernel to a version containing the fix. Restrict the ability to configure perf event filters to trusted users.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS