CVE-2026-45712: Mailpit is an email testing tool and API for developers

Q: How do I fix CVE-2026-45712?

mailpit: upgrade to 1.30.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-45712 being exploited?

CVE-2026-45712 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-45712 affect?

CVE-2026-45712 affects mailpit. Severity is medium (CVSS 5.9). Mailpit is an email testing tool and API for developers. Prior to version 1.30.0, the screenshot/print proxy (/proxy?data=…) maintains a package-level assets map[string]MessageAssets cache, but reads the map without holding assetsMutex whil

Q: How urgent is CVE-2026-45712?

Priority 37/100. Public exploit reference; Remotely exploitable, no login, no user action

This week

MEDIUM 5.9REMOTEUPGRADE

CVE-2026-45712 is a medium-severity flaw (CVSS 5.9) affecting mailpit. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Mailpit is an email testing tool and API for developers. Prior to version 1.30.0, the screenshot/print proxy (/proxy?data=…) maintains a package-level assets map[string]MessageAssets cache, but reads the map without holding assetsMutex while a long-running cleanup goroutine and (re-entrant) CSS-rewriting code path concurrently write to it under the lock. When the unsynchronized read coincides with a synchronized write, Go's runtime raises fatal e

Why this priority

Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 74%)
CISA exploited list	No
Weakness	CWE-362, CWE-770
Published	2026-07-20
Last modified	2026-10-24

Publisher (CNA): GitHub, Inc. · Vendor: axllent

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-20 16:17 UTCPublished CVE record published
2026-10-24 20:10 UTCUpdated Record last modified

axllent mailpit UPGRADE

Affected: < 1.30.0

Fixed in: 1.30.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy mailpit || rpm -q mailpit || mailpit --version

2. UPGRADE to 1.30.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade mailpit

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mailpit

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-45712?

mailpit: upgrade to 1.30.0. Exact commands for each OS are on this page.

Is CVE-2026-45712 being exploited?

CVE-2026-45712 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-45712 affect?

CVE-2026-45712 affects mailpit. Severity is medium (CVSS 5.9). Mailpit is an email testing tool and API for developers. Prior to version 1.30.0, the screenshot/print proxy (/proxy?data=…) maintains a package-level assets map[string]MessageAssets cache, but reads the map without holding assetsMutex whil

How urgent is CVE-2026-45712?

Priority 37/100. Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-45713 HIGH 7.5 UPGRADE Mailpit is an email testing tool and API for developers
CVE-2026-48824 MEDIUM 5.3 UPGRADE Mailpit is an email testing tool and API for developers
CVE-2026-45709 MEDIUM 5.8 UPGRADE Mailpit is an email testing tool and API for developers
CVE-2026-45711 MEDIUM 5.9 UPGRADE Mailpit is an email testing tool and API for developers

References

← Back to latest CVEs