Mailpit is an email testing tool and API for developers. Prior to version 1.30.0, the Mailpit SMTP server has a Server.MaxSize int field that controls the maximum allowed DATA payload size, but the field is never assigned anywhere outside test code, leaving it at Go's zero value (0 ⇒ "no limit"). The same applies to the HTTP /api/v1/send endpoint, whose request body is decoded with json.NewDecoder(r.Body) and no http.MaxBytesReader. Because Mailpit's default listeners bind [::]:1025 (SMTP) and [::]:8025 (HTTP), with no authentication required on either, a single network-reachable attacker can push an arbitrarily large message into Mailpit and watch RAM consumption spike with a ~7-10× amplification factor (raw frame → enmime envelope tree → search-text index → zstd-encoded write to SQLite). Repeating the attack — or running it concurrently from multiple connections — drives the process to OOM-kill. Version 1.30.0 contains a patch.
CVE-2026-45713
This high-severity CVE scores 7.5 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit probability: 0.1%, top 73% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(low)
- EG Risk
- —
- EPSS
- 24.1%
- KEV
- Not listed
Published
May 19, 2026
Last Modified
July 21, 2026
Advisory Details (2)
Auto-updated Jul 20, 2026Unauthenticated remote memory-exhaustion DoS via unlimited SMTP DATA and /api/v1/send body sizes · Advisory · axllent/mailpit · GitHub
https://github.com/axllent/mailpit/security/advisories/GHSA-fpxj-m5q8-fphwRelease v1.30.0 (axllent/mailpit)
Patch available: axllent/mailpit v1.30.0
https://github.com/axllent/mailpit/releases/tag/v1.30.0Vendor Advisories for CVE-2026-45713(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
Go(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| github.com/axllent/mailpit | — | 1.30.0 | — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 2× in last 7d / 2× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:24 UTCEPSS rescore
- 2026-06-14 23:18 UTCEPSS rescore
- 2026-06-13 23:00 UTCEPSS rescore
- 2026-06-12 23:12 UTCEPSS rescore
- 2026-05-24 06:14 UTCEG score recompute
Related CVEs(same CWE)
Same CWE
10 shownCWE-400 · CWE-770
- CVE-2011-3192NVD 0.0EG 9.0EPSS 100%NONE
- CVE-2004-1464NVD 5.9EG 9.0 KEVEPSS 92%MEDIUM
- CVE-2006-1364NVD 7.5EG 8.2EPSS 99%HIGH
- CVE-2008-5180NVD 5.3EG 7.9EPSS 99%MEDIUM
- CVE-2007-20001EG 7.5HIGH
- CVE-2002-20001EG 7.5EPSS 98%HIGH
- CVE-2012-0785EG 7.5HIGH
- CVE-2012-5366EG 7.5HIGH
- CVE-2012-5365EG 7.5HIGH
- CVE-2012-5364EG 7.5EPSS 96%HIGH
Frequently asked(5)
What is CVE-2026-45713?
When was CVE-2026-45713 disclosed?
Is CVE-2026-45713 actively exploited?
What is the CVSS score of CVE-2026-45713?
How do I remediate CVE-2026-45713?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-45713
Is Your Infrastructure Affected by CVE-2026-45713?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.