Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
axllent mailpit — Mailpit: Concurrent map read & write in proxy CSS rewriter - remote unauth crash (fatal error: concurrent map read and map write)
AV AC PR UI S C I A CVSS EPSS %ile KEV
N H N N U N N H 5.9 .0025 16.3 —
AFFECTED
Product Versions Fixed
mailpit < 1.30.0 – —
TIMELINE
May 13 Reserved by GitHub_M
Jul 20 EXPLOIT PUBLISHED — CVE-2026-45712 (axllent mailpit). Public exploit reference added.
Jul 20 Published (CNA: GitHub_M)
Description
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 error: concurrent map read and map write — a runtime.throw that is not recoverable by http.Server's handler-panic recover. The whole Mailpit process exits, taking the SMTP, POP3 and HTTP listeners down with it. Version 1.30.0 contains a patch.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
|---|
| May 13, 2026 | Reserved | Reserved by GitHub_M |
| July 20, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-45712 (axllent mailpit). Public exploit reference added. |
| July 20, 2026 | Published | Published (CNA: GitHub_M) |
Affected
Affected products and packages — 1 row
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| axllent | mailpit | — | < 1.30.0 | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-45712 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.