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NVD / CVE Program· CNA GitHub_M

CVE-2026-56739: Logto: SSRF via Webhooks and Custom OAuth2 Connector UserInfo Endpoint

Noroxi assessment

Priority: Monitor (action score 34/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.29% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. Administrator privileges are required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: logto-io logto 1.43.0.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to logto-io logto 1.43.0 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 8.5 · v4.0—No exploit Fix available
Published
Sep 24, 2026
Updated
Sep 28, 2026
EPSS
0.2% · 22th percentile

Report tools

JSON

Action score

34

Monitor

Low priority for now.

CVSS
34 / 40 · 8.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
8.5
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:L/VA:L/SC:H/SI:H/SA:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • logto-io logto

    • < 1.43.0affected

Same product

logto-io: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-63188logto-tunnel serves files outside --experience-path via path traversal
    34Monitor
  • CVE-2026-55789Logto: SAML IdP injects user-controlled profile attributes raw into signed assertions, allowing privilege escalation at relying Service Providers
    34Monitor
  • CVE-2026-82263Logto Server-Side Request Forgery via OIDC SSO Connector Issuer URL
    32Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-63187Aug 19, 2026 · Logto: OS command injection vulnerability exists in the Commitlint workflow
    25Monitor
  • ← EarlierCVE-2026-82262Aug 28, 2026 · Logto Server-Side Request Forgery via webhook test endpoint
    32Monitor
  • ← EarlierCVE-2026-63203Sep 24, 2026 · Logto: Account API can disclose stored third-party provider tokens without the identities scope
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
logto-io logto1.43.0 · descriptionVendor (CNA)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-8226227 days apartLogto Server-Side Request Forgery via webhook test endpoint
    32Monitor
  • CVE-2026-8226327 days apartLogto Server-Side Request Forgery via OIDC SSO Connector Issuer URL
    32Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

  • CVE-2026-5537776 days apartLogto: Account Center MFA management step-up bypass via WebAuthn registration verification
    32Monitor
  • CVE-2026-5537076 days apartLogto: TOTP code can be replayed within the RFC 6238 validity window (one-time use violation)
    25Monitor

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • Administrator privileges are required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
High
User interaction
None
Scope
X

Weakness class (CWE)

CWE-918 · Server-Side Request Forgery (SSRF)

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:L/VA:L/SC:H/SI:H/SA:H/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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓
  2. SSVC exploitation— → none

For records you follow, these changes also arrive as notifications. →

References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records