LibreChat is a ChatGPT clone with additional features. Prior to version 0.8.3, isPrivateIP() in packages/api/src/auth/domain.ts fails to detect IPv4-mapped IPv6 addresses in their hex-normalized form, allowing any authenticated user to bypass SSRF protection and make the server issue HTTP requests to internal network resources — including cloud metadata services (e.g., AWS 169.254.169.254), loopback, and RFC1918 ranges. Version 0.8.3 fixes the issue.
CVE-2026-31943
HIGHPre-NVD 8.58.5
EchelonGraph scoreLOW confidence
This high-severity CVE scores 8.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: secondary
8.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.5Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.5
- EG Score
- 8.5(low)
- EG Risk
- 43(Track)EG Risk 43/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity85% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 12%
- KEV
- Not listed
Published
March 27, 2026
Last Modified
June 17, 2026
References (2)
- security-advisories@githubhttps://github.com/danny-avila/LibreChat/security/advisories/GHSA-w5r7-4f94-vp4c
- 134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/danny-avila/LibreChat/security/advisories/GHSA-w5r7-4f94-vp4c
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 2× in last 7d / 2× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-28 15:36 UTCEPSS rescore
- 2026-07-27 14:19 UTCEG score recompute
Related CVEs(same CWE)
Same CWE
10 shownCWE-918
- CVE-2016-10927EG 10.0CRITICAL
- CVE-2016-10926EG 10.0CRITICAL
- CVE-2018-10511EG 10.0CRITICAL
- CVE-2018-1000124EG 10.0CRITICAL
- CVE-2017-11291EG 10.0EPSS p92CRITICAL
- CVE-2017-12905EG 10.0CRITICAL
- CVE-2017-8794EG 10.0CRITICAL
- CVE-2017-13667EG 9.9CRITICAL
- CVE-2017-17674EG 9.8CRITICAL
- CVE-2013-4864EG 9.8EPSS p93CRITICAL
Frequently asked(5)
What is CVE-2026-31943?
CVE-2026-31943 is a high vulnerability published on March 27, 2026. LibreChat is a ChatGPT clone with additional features. Prior to version 0.8.3, isPrivateIP() in packages/api/src/auth/domain.ts fails to detect IPv4-mapped IPv6 addresses in their hex-normalized form, allowing any authenticated user to bypass SSRF protection and make the server issue HTTP requests…
When was CVE-2026-31943 disclosed?
CVE-2026-31943 was first published in the National Vulnerability Database on March 27, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-31943 actively exploited?
CVE-2026-31943 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 88.2% of all scored CVEs.
What is the CVSS score of CVE-2026-31943?
CVE-2026-31943 has a CVSS v3 base score of 8.5 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-31943?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-31943, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-31943
Is Your Infrastructure Affected by CVE-2026-31943?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.