LOIDC nonce validation bypass

published 2026-07-23 3 mo ago modified 2026-07-27 3 mo ago also EUVD-2026-48304

cvss: 9.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits: 0; none known

Logto bypasses OIDC nonce validation when the nonce claim is absent from the id_token, enabling replay of authentication tokens and weakening session-binding.

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: total
Assessed: 3 mo ago (2026-07-27)

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	9.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CNA	3.1	9.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected products

Logto Logto

Classification

Weakness

CWE-345 Insufficient Verification of Data Authenticity

References

github.com /logto-io/logto/blob/ea3ede35028dfd0bbb6d7b239623ce0e7f6cdff8/packages/core/src/sso/OidcConnector/utils.ts#L17

Sources

CVE List CVE-2026-15612
NVD CVE-2026-15612

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary