Is CVE-2026-45712 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-45712 being exploited in the wild.

How severe is CVE-2026-45712?

Medium severity, with a CVSS score of 5.9, published 20 July 2026.

Which products and versions are affected?

Axllent Mailpit < 1.30.0; github.com/axllent/mailpit (Go) < 1.30.0, SEMVER:introduced=0,fixed=1.30.0.

Is there a fix for CVE-2026-45712?

Yes. github.com/axllent/mailpit (Go): upgrade to 1.30.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-45712 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-45712?

Check whether you run Axllent Mailpit or github.com/axllent/mailpit (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-45712: axllent Mailpit denial of service via race condition in proxy handler

Q: Which products and versions are affected?

Axllent Mailpit < 1.30.0; github.com/axllent/mailpit (Go) < 1.30.0, SEMVER:introduced=0,fixed=1.30.0.

Q: Is there a fix for CVE-2026-45712?

Yes. github.com/axllent/mailpit (Go): upgrade to 1.30.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-45712 attacked?

It is attacked over the network, in a network appliance.

Q: Am I affected by CVE-2026-45712?

Check whether you run Axllent Mailpit or github.com/axllent/mailpit (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-45712 · Severity: medium · CVSS 5.9 · Published 2026-07-20

Mailpit is an email testing tool used by developers to capture and view outgoing emails during software development. A flaw in how the tool handles internal data allows a remote attacker to crash the entire application by sending specifically crafted requests. This results in a total service outage, preventing developers from receiving or testing emails until the process is manually restarted.

Technologies: Axllent Mailpit, github.com/axllent/mailpit (Go). Vendors: Axllent, Go.

Quick answers

Is CVE-2026-45712 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-45712 being exploited in the wild.
How severe is CVE-2026-45712?: Medium severity, with a CVSS score of 5.9, published 20 July 2026.
Which products and versions are affected?: Axllent Mailpit < 1.30.0; github.com/axllent/mailpit (Go) < 1.30.0, SEMVER:introduced=0,fixed=1.30.0.
Is there a fix for CVE-2026-45712?: Yes. github.com/axllent/mailpit (Go): upgrade to 1.30.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-45712 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-45712?: Check whether you run Axllent Mailpit or github.com/axllent/mailpit (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

github.com/axllent/mailpit (Go): upgrade to 1.30.0 or later
```
go get github.com/axllent/mailpit@v1.30.0
```

Technical details

A race condition exists in the Mailpit screenshot/print proxy (/proxy?data=...) due to improper synchronization of a package-level assets map. The application performs unsynchronized reads on the map while a background cleanup goroutine and CSS-rewriting logic perform synchronized writes. Because Go's runtime raises a non-recoverable fatal error upon detecting concurrent map access, the entire Mailpit process terminates, including SMTP, POP3, and HTTP listeners. An unauthenticated attacker can trigger this by planting a message with a stylesheet link and issuing concurrent requests to the proxy endpoint. The issue is fixed in version 1.30.0.

Affected products

axllent Mailpit < 1.30.0

Identifiers

CVE-2026-45712
GHSA-w4vj-r5pg-3722
GO-2026-5689

Timeline

2026-05-14: patched: Version 1.30.0 released
2026-07-20: disclosed: CVE-2026-45712 published

References

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