CVE-2026-77568Network attack vectorHinoki check available

CSRF bypass via reusable compressed session tokens

Published Sep 18, 2026 · Updated Sep 18, 2026

CSRF weakness in Mojolicious Mojo before 9.48 allows remote attackers to recover tokens and forge requests through a BREACH side channel. The _csrf_token helper caches one secret per session, and csrf_field emits the same token unchanged into every rendered response. Exploitation requires compressed HTML that reflects attacker-influenced content, many induced victim requests, and response-size observation; API-only deployments are unaffected.

CVSS severity4.2
Medium
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

CSRF weakness in Mojolicious Mojo before 9.48 allows remote attackers to recover tokens and forge requests through a BREACH side channel. The _csrf_token helper caches one secret per session, and csrf_field emits the same token unchanged into every rendered response. Exploitation requires compressed HTML that reflects attacker-influenced content, many induced victim requests, and response-size observation; API-only deployments are unaffected.

The record

CVE
CVE-2026-77568
Published
Sep 18, 2026
Updated
Sep 18, 2026
Vendor
Mojolicious
Product
Mojo
Classifications
CWE-200, CWE-352
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 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=< 9.48

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mojolicious · Mojoversion=< 9.48

Published CVSS scores

4.2GitHub CNACVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
CWE-352Cross-Site Request Forgery (CSRF)

Public exploit references

No public exploit references are available in this record.

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Technologies

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Your stack

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