CVE-2026-56739

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: —CVSS: 8.5Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Logto is the modern, open-source auth infrastructure for SaaS and AI apps. Prior to 1.43.0, Logto fetches administrator-controlled outbound destinations without validating the address used for the connection. Webhook delivery in packages/core/src/libraries/hook/utils.ts can reach special-use and cloud metadata addresses. Custom OAuth2 connectors can use an attacker-selected userInfoEndpoint and forward the OAuth access token in the Authorization header, while OIDC connectors can fetch an attacker-selected jwksUri. The affected operations require tenant administrative configuration access, but they cross the server's network boundary and can expose internal data or upstream provider credentials. This issue is fixed in version 1.43.0.

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 computed
Severity85% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
—
EPSS %ILE
—
KEV
Not listed

Published

September 24, 2026

Last Modified

September 24, 2026

Advisory Details (4)

Auto-updated Sep 24, 2026
Patch available. Sources: github, github_pr, github_commit, github_release.
github_release Patch Available

v1.43.0

Patch available: logto-io/logto v1.43.0

https://github.com/logto-io/logto/releases/tag/v1.43.0
github_commit Patch Available

commit 16f4b2e732d5 (logto-io/logto)

Patch available: logto-io/logto v1.43.0 (contains commit 16f4b2e732d5)

https://github.com/logto-io/logto/commit/16f4b2e732d5114ac98646c9370ec6ab61d6ed26
github_pr Patch Available

fix(core,shared): block SSRF in webhook and SSO outbound requests

Patch available: logto-io/logto v1.43.0 (PR #9501 merged 2026-08-27)

https://github.com/logto-io/logto/pull/9501
github Patch Available

SSRF via Webhooks and Custom OAuth2 Connector UserInfo Endpoint (CWE-918) · Advisory · logto-io/logto · GitHub

https://github.com/logto-io/logto/security/advisories/GHSA-3556-624q-c5w3

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 3× in last 7d / 3× 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.

  1. 2026-09-24 16:34 UTCEG score recompute
  2. 2026-09-24 15:32 UTCEG score recompute
  3. 2026-09-24 15:31 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(4)

What is CVE-2026-56739?
CVE-2026-56739 is a high vulnerability published on September 24, 2026. Logto is the modern, open-source auth infrastructure for SaaS and AI apps. Prior to 1.43.0, Logto fetches administrator-controlled outbound destinations without validating the address used for the connection. Webhook delivery in packages/core/src/libraries/hook/utils.ts can reach special-use and…
When was CVE-2026-56739 disclosed?
CVE-2026-56739 was first published in the National Vulnerability Database on September 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-56739?
CVE-2026-56739 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-2026-56739?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56739, 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

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