CVE-2026-15612Network attack vector

Authentication replay via absent nonce claim

Published Jul 23, 2026 · Updated Jul 23, 2026

Improper OIDC nonce validation in Logto 1.10.1 through 1.37.1 allows remote attackers to replay identity tokens during SSO. In the OIDC connector response validator, the nonce comparison runs only when data.nonce is present, so an omitted claim skips verification against nonceFromSession. An attacker must reach a configured OIDC SSO flow and obtain or replay an otherwise accepted ID token; success breaks session binding and can grant access as the token subject.

CVSS severity9.1
Critical
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper OIDC nonce validation in Logto 1.10.1 through 1.37.1 allows remote attackers to replay identity tokens during SSO. In the OIDC connector response validator, the nonce comparison runs only when data.nonce is present, so an omitted claim skips verification against nonceFromSession. An attacker must reach a configured OIDC SSO flow and obtain or replay an otherwise accepted ID token; success breaks session binding and can grant access as the token subject.

The record

CVE
CVE-2026-15612
Published
Jul 23, 2026
Updated
Jul 23, 2026
Vendor
Logto
Product
Logto
Classifications
CWE-345, T1078
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=1.10.1 <=1.37.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Logto · Logtoversion=1.10.1 <=1.37.1

Published CVSS scores

9.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-345Insufficient Verification of Data Authenticity
T1078Valid Accounts

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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