CVE-2026-45712Public exploitNetwork attack vector

Service termination via unsynchronized proxy cache access

Published Jul 20, 2026 · Updated Jul 20, 2026

Race condition in Axllent Mailpit before 1.30.0 allows remote attackers to terminate the service through concurrent proxy requests. The screenshot and print proxy reads its package-level assets cache without assetsMutex while cleanup and CSS rewriting update the same map. An attacker needs unauthenticated HTTP access and the ability to place a CSS-linked message; exploitation exits the process and stops SMTP, POP3, and HTTP listeners.

CVSS severity5.9
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in Axllent Mailpit before 1.30.0 allows remote attackers to terminate the service through concurrent proxy requests. The screenshot and print proxy reads its package-level assets cache without assetsMutex while cleanup and CSS rewriting update the same map. An attacker needs unauthenticated HTTP access and the ability to place a CSS-linked message; exploitation exits the process and stops SMTP, POP3, and HTTP listeners.

The record

CVE
CVE-2026-45712
Published
Jul 20, 2026
Updated
Jul 20, 2026
Vendor
Axllent
Product
Mailpit
Classifications
CWE-362, CWE-770, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 20, 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=< 1.30.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Axllent · Mailpitversion=< 1.30.0

Published CVSS scores

5.9GitHub Security AdvisoryCVSS:3.1/AV:N/AC:H/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-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CWE-770Allocation of Resources Without Limits or Throttling
T1499.004Application or System Exploitation

Public exploit references

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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