Dashboard / CVE-2026-124683

CVE-2026-124683

HIGH
MEDIUM Priority: 0.04 BB Relevance: 77/100
Published: 2026-11-09 Modified: 2026-11-12 First seen: 2026-11-09 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: X
AT: None
VC: None
VI: None
VA: High

Description

Eclipse Langium versions 3.2.0 through 4.4.0 contain an inefficient algorithmic complexity issue (CWE-407) in the opt-in IndentationAwareTokenBuilder and IndentationAwareLexer. When producing DEDENT tokens, the token builder recomputes line numbers by re-scanning the entire preceding document text. A document whose indentation changes on most lines then takes quadratic time to tokenize. Because tokenization is synchronous, a crafted document of a few hundred kilobytes can block the Node.js event loop for tens of seconds. That causes a DoS for every user served by the same process. Languages built with the DefaultLexer and DefaultTokenBuilder are unaffected.

Weakness Classification (1)

Affected Software (2)

VendorProductVersion
Eclipse Foundation Eclipse Langium 3.2.0
Eclipse Foundation Eclipse Langium 3.2.0

References & Advisories (3)

Bug Bounty Relevance

77 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

8.7 / 10.0 v4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.50%
Raw Score 0.004950
Percentile 43.1%
Date 2026-11-13

EPSS Trend

2026-11-13
0.00495
2026-11-12
0.00495
2026-11-10
0.00495

Intelligence Sources

mitre ref →
nvd ref →

External Links