CVE-2026-45754Network attack vector

Unauthenticated event injection via ignored webhook secrets

Published Jul 14, 2026 · Updated Jul 14, 2026

Authentication bypass in affected Symfony Mailjet and LOX24 bridges allows remote attackers to inject forged webhook events. The bridges' doParse methods accept a configured secret but never read it, instead converting and returning each POST payload unconditionally. Exposure requires an application-wired webhook endpoint whose URL is known; forged delivery, bounce, spam, open, or click events can corrupt suppression lists and metrics.

CVSS severity6.9
Medium
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in affected Symfony Mailjet and LOX24 bridges allows remote attackers to inject forged webhook events. The bridges' doParse methods accept a configured secret but never read it, instead converting and returning each POST payload unconditionally. Exposure requires an application-wired webhook endpoint whose URL is known; forged delivery, bounce, spam, open, or click events can corrupt suppression lists and metrics.

The record

CVE
CVE-2026-45754
Published
Jul 14, 2026
Updated
Jul 14, 2026
Vendor
Symfony
Product
Symfony Mailjet Mailer Bridge
Classifications
CWE-287, CWE-306, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 14, 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=>= 6.4.0, < 6.4.40
  2. Affected versionversion=>= 7.0.0-BETA1, < 7.4.12
  3. Affected versionversion=>= 8.0.0-BETA1, < 8.0.12

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Symfony · Symfony Mailjet Mailer Bridgeversion=>= 6.4.0, < 6.4.40; version=>= 7.0.0-BETA1, < 7.4.12; version=>= 8.0.0-BETA1, < 8.0.12
Symfony · Symfony LOX24 Notifier Bridgeversion=>= 7.1.0-BETA1, < 7.4.12; version=>= 8.0.0-BETA1, < 8.0.12
Symfony · Symfonyversion=>= 6.4.0, < 6.4.40; version=>= 7.0.0-BETA1, < 7.4.12; version=>= 8.0.0-BETA1, < 8.0.12

Published CVSS scores

6.9GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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.

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
CWE-306Missing Authentication for Critical Function
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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

Technologies

Your stack

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Your stack

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