CVE-2026-88355

Incorrect Buffer Size Calculation in Tinyexpr Leading to Process Crash

Published Sep 24, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
An incorrect buffer size calculation vulnerability exists in tinyexpr commit 4a7456e in new_expr(). For arity-0 expression nodes, including constants, variables, and zero-argument functions, the function allocates less memory than sizeof(te_expr) but treats the returned allocation as a complete te_expr object. This results in undefined behavior and can cause deterministic process termination in UBSan-instrumented builds.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Incorrect Buffer Size Calculation in Tinyexpr Leading to Process Crash
Type Values Removed Values Added
Title Buffer Size Miscalculation in tinyexpr's Expression Parser Causes Undefined Behavior and Possible Crash
Weaknesses CWE-119
Type Values Removed Values Added
Weaknesses CWE-131
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Type Values Removed Values Added
First Time appeared Codeplea
Codeplea tinyexpr
Vendors & Products Codeplea
Codeplea tinyexpr
Type Values Removed Values Added
Title Buffer Size Miscalculation in tinyexpr's Expression Parser Causes Undefined Behavior and Possible Crash
Weaknesses CWE-119
Type Values Removed Values Added
Description An incorrect buffer size calculation vulnerability exists in tinyexpr commit 4a7456e in new_expr(). For arity-0 expression nodes, including constants, variables, and zero-argument functions, the function allocates less memory than sizeof(te_expr) but treats the returned allocation as a complete te_expr object. This results in undefined behavior and can cause deterministic process termination in UBSan-instrumented builds.
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Oct 6, 2026, 5:42 PM
Reserved
Sep 10, 2026, 12:00 AM
Status
Deferred
Published
Sep 24, 2026, 4:17 PM
Modified
Oct 6, 2026, 6:16 PM