CVE-2026-88355

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.

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.4% chance of exploitation in the next 30 days; higher than 35% of CVEs (scores of 2026-10-25)

CWE

CWE-131

Published

2026-09-24

Modified

2026-10-06

Record from

the NVD, synced 2026-10-19

References

• https://github.com/codeplea/tinyexpr/issues/145
• https://github.com/szaydel/tinyexpr/commit/fe7459728c2ab8d2f91365abe56601cdd0e24f9b
• https://github.com/codeplea/tinyexpr/issues/145

Check your stackJSON