Vulnerability in Le0pard Re2js
CVE-2026-116795
RE2JS is the JavaScript port of RE2, a regular expression engine that provides linear time matching. From 2.2.0 until 2.8.7, enabling LOOKBEHINDS and using repeated matching through matcher().find(), matchAll(), split(), or matcher().replaceAll() can cause quadratic total work. Machine.match restarts lookbehind scanning from offset zero for each requested start position, while Matcher-based APIs request capture slots that prevent the early exit used for captureless matching. Dense matches therefore repeatedly rescan the input, allowing attacker-influenced text to monopolize a single-threaded worker and deny service. This issue is fixed in version 2.8.7.
Published .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Le0pard Re2js — versions >= 2.2.0, < 2.8.7
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-116795?
- CVE-2026-116795 is a high-severity vulnerability in Le0pard Re2js, classified under Inefficient Algorithmic Complexity. CVSS score: 7.5/10. Published 2026-10-28.
- How severe is CVE-2026-116795?
- High severity. CVSS v3 base score is 7.5 out of 10.