CVE-2026-45713Public exploitNetwork attack vector

Unauthenticated memory exhaustion via unlimited message bodies

Published Jul 20, 2026 · Updated Jul 20, 2026

Resource exhaustion in Axllent Mailpit before 1.30.0 allows remote attackers to crash the service through oversized SMTP or HTTP messages. The SMTP server leaves Server.MaxSize at zero, while /api/v1/send decodes an unbounded request body, allowing both paths to retain and amplify attacker-controlled data. Default listeners expose both paths without authentication, and repeated or concurrent requests can drive the process to an out-of-memory kill.

CVSS severity7.5
High
EPSS probability0.39%
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

Resource exhaustion in Axllent Mailpit before 1.30.0 allows remote attackers to crash the service through oversized SMTP or HTTP messages. The SMTP server leaves Server.MaxSize at zero, while /api/v1/send decodes an unbounded request body, allowing both paths to retain and amplify attacker-controlled data. Default listeners expose both paths without authentication, and repeated or concurrent requests can drive the process to an out-of-memory kill.

The record

CVE
CVE-2026-45713
Published
Jul 20, 2026
Updated
Jul 20, 2026
Vendor
Axllent
Product
Mailpit
Classifications
CWE-400, 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

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=< 1.30.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Axllent · Mailpitversion=< 1.30.0

Published CVSS scores

7.5GitHubCVSS: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-400Uncontrolled Resource Consumption
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

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