CVE-2025-29786

A flaw was found in Expr. This vulnerability allows excessive memory usage and potential out-of-memory (OOM) crashes via unbounded input strings, where a malicious or inadvertent large expression can cause the parser to construct an extremely large Abstract Syntax Tree (AST), consuming excessive memory.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this vulnerability, it is recommended to impose an input size restriction before parsing (i.e. validating or limiting the length of expression strings that the application will accept). Ensuring no unbounded-length expressions are fed into the parser will prevent the parser from constructing a very large AST and avoid the potential memory exhaustion issue.