CVE-2026-124683

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Source
https://cve.org/CVERecord?id=CVE-2026-124683
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-124683.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-124683
Aliases
  • GHSA-297v-g8mm-qj4h
Published
2026-11-09T16:02:50Z
Modified
2026-11-10T02:41:16Z
Severity
  • 8.7 (High) CVSS_V4 - 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 CVSS Calculator
Summary
[none]
Details

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.

Database specific 
{
    "cna_assigner": "eclipse",
    "cwe_ids": [
        "CWE-407"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/124xxx/CVE-2026-124683.json"
}
References

Affected packages

Git / github.com/eclipse-langium/langium

Affected ranges

Type
GIT
Repo
https://github.com/eclipse-langium/langium
Events
Introduced
b2a6fe9684434117eb6a344fc2721e3c26d989bf
Last Affected
89d49680b39218af2e5b700cd3f4fdc122600ac4
Database specific
Show details 
{
    "extracted_events": [
        {
            "range": [
                {
                    "introduced": "3.2.0"
                },
                {
                    "last_affected": "4.4.0"
                }
            ],
            "source": "AFFECTED_FIELD",
            "strategy": "StandardRange"
        }
    ]
}

Affected versions

v3.*
v3.2.0
v3.3.1
v3.4.0
v3.5.0
v4.*
v4.0.0
v4.1.0
v4.2.0
v4.3.0
v4.4.0

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-124683.json"