SCA: security update for github.com/expr-lang/expr (GHSA-93mq-9ffx-83m2)

high Tenable Self-Hosted Container Security Plugin ID 421139

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

- Expr is an expression language and expression evaluation for Go. Prior to version 1.17.0, if the Expr
expression parser is given an unbounded input string, it will attempt to compile the entire string and
generate an Abstract Syntax Tree (AST) node for each part of the expression. In scenarios where input size
isn’t limited, a malicious or inadvertent extremely large expression can consume excessive memory as the
parser builds a huge AST. This can ultimately lead to*excessive memory usage and an Out-Of-Memory (OOM)
crash of the process. This issue is relatively uncommon and will only manifest when there are no
restrictions on the input size, i.e. the expression length is allowed to grow arbitrarily large. In
typical use cases where inputs are bounded or validated, this problem would not occur. The problem has
been patched in the latest versions of the Expr library. The fix introduces compile-time limits on the
number of AST nodes and memory usage during parsing, preventing any single expression from exhausting
resources. Users should upgrade to Expr version 1.17.0 or later, as this release includes the new node
budget and memory limit safeguards. Upgrading to v1.17.0 ensures that extremely deep or large expressions
are detected and safely aborted during compilation, avoiding the OOM condition. For users who cannot
immediately upgrade, the recommended workaround is to impose an input size restriction before parsing. In
practice, this means validating or limiting the length of expression strings that your application will
accept. For example, set a maximum allowable number of characters (or nodes) for any expression and reject
or truncate inputs that exceed this limit. By ensuring no unbounded-length expression is ever fed into the
parser, one can prevent the parser from constructing a pathologically large AST and avoid potential memory
exhaustion. In short, pre-validate and cap input size as a safeguard in the absence of the patch.
(CVE-2025-29786)

Plugin Details

Severity: High

ID: 421139

Version: Revision 1.11

Type: Local

Family: SCA Checks

Published: 3/18/2025

Updated: 7/2/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.92

Vendor

Vendor Severity: High

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

CVSS Score Source: CVE-2025-29786

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 3/17/2025

Vulnerability Publication Date: 3/17/2025

Reference Information

CVE: CVE-2025-29786

cwe: CWE-770

Detections

Analytics