CVE-2026-62317Public exploitNetwork attack vector

Unauthenticated service interrupt via regex backtracking

Published Aug 19, 2026 · Updated Aug 19, 2026

ReDoS in Logto before 1.41.0 allows remote attackers to interrupt authentication services via crafted email verification requests. In packages/core/src/libraries/sign-in-experience/email-blocklist-policy.ts, the email subaddressing check builds a RegExp from the attacker-controlled domain segment and tests the full address, so metacharacters and extra at signs drive catastrophic backtracking. Reachability requires blockSubaddressing to be enabled, and repeated POST /api/experience/verification/verification-code requests can stall the Node.js event loop and make sign-in, token issuance, SSO, and the administrative console unavailable.

CVSS severity7.5
High
EPSS probability0.63%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

ReDoS in Logto before 1.41.0 allows remote attackers to interrupt authentication services via crafted email verification requests. In packages/core/src/libraries/sign-in-experience/email-blocklist-policy.ts, the email subaddressing check builds a RegExp from the attacker-controlled domain segment and tests the full address, so metacharacters and extra at signs drive catastrophic backtracking. Reachability requires blockSubaddressing to be enabled, and repeated POST /api/experience/verification/verification-code requests can stall the Node.js event loop and make sign-in, token issuance, SSO, and the administrative console unavailable.

The record

CVE
CVE-2026-62317
Published
Aug 19, 2026
Updated
Aug 19, 2026
Vendor
Logto
Product
Logto
Classifications
CWE-1333, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.41.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Logto · Logtoversion=< 1.41.0

Published CVSS scores

7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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 exploitPublished

Weakness, pattern, technique

CWE-1333Inefficient Regular Expression Complexity
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo