CVE-2026-9733Network attack vector

Session hijacking via predictable OAuth state

Published Jun 23, 2026 · Updated Jun 23, 2026

Cross-site request forgery in Mojolicious::Plugin::Web::Auth::OAuth2 through 0.17 allows remote attackers to hijack user sessions. The default _state_generator hashes the HTTP Date-derived epoch time and Perl rand output with SHA-1, producing a predictable OAuth state value. The flaw is reachable when an application omits a custom state generator, enabling forged authorization responses to bind an attacker's OAuth identity to a victim's application session.

CVSS severity9.1
Critical
EPSS probability0.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site request forgery in Mojolicious::Plugin::Web::Auth::OAuth2 through 0.17 allows remote attackers to hijack user sessions. The default _state_generator hashes the HTTP Date-derived epoch time and Perl rand output with SHA-1, producing a predictable OAuth state value. The flaw is reachable when an application omits a custom state generator, enabling forged authorization responses to bind an attacker's OAuth identity to a victim's application session.

The record

CVE
CVE-2026-9733
Published
Jun 23, 2026
Updated
Jun 23, 2026
Vendor
Hayato Imai
Product
Mojolicious::Plugin::Web::Auth
Classifications
CWE-340, CWE-338, CAPEC-62, CAPEC-59, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 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?

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

  1. Affected versionversion=0 <=0.17

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Hayato Imai · Mojolicious::Plugin::Web::Authversion=0 <=0.17

Published CVSS scores

9.1CISACVSS: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-340Generation of Predictable Numbers or Identifiers
CWE-338Use of Cryptographically Weak Pseudo-Random Number Generator
CAPEC-62Cross Site Request Forgery
CAPEC-59Session Credential Falsification through Prediction
T1190Exploit Public-Facing Application

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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