CVE-2026-67445

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 70% 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).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Mailpit is an email testing tool and API for developers. Prior to 1.30.4, Mailpit reads SMTP commands through internal/smtpd/smtpd.go session.readLine() using bufio.Reader.ReadString before session.parseLine() parses the verb or the RFC 5321 512-octet command-line limit is enforced. An unauthenticated remote SMTP client can send an oversized single command line that is fully allocated before syntax rejection or timeout, and the normal MaxMessageSize and DATA limits do not apply to this pre-DATA path. The same command reader is used by handleAuthLogin(), handleAuthPlain(), and handleAuthCramMD5() continuation lines, so concurrent oversized inputs can create memory pressure and reduce service availability. This issue is fixed in version 1.30.4.

CVSS v3
5.3
EG Score
5.3(medium)
EG Risk
39(Track)
EG Risk 39/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity53% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
30%
KEV
Not listed

Published

August 20, 2026

Last Modified

August 21, 2026

Advisory Details (3)

Auto-updated Aug 20, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github.
github Patch Available🟡 PoC Available

SMTP command parser buffers unbounded command lines before syntax rejection · Advisory · axllent/mailpit · GitHub

https://github.com/axllent/mailpit/security/advisories/GHSA-w878-pj84-3j5v
github_release Patch Available

Release v1.30.4 (axllent/mailpit)

Patch available: axllent/mailpit v1.30.4

https://github.com/axllent/mailpit/releases/tag/v1.30.4
github_commit

commit 993bed95b3c7 (axllent/mailpit)

Fix landed in axllent/mailpit commit 993bed95b3c7 — awaiting tagged release

https://github.com/axllent/mailpit/commit/993bed95b3c74d95231af93bd0e0d4c3d5b4db4d

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 10× in last 7d / 17× 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.

  1. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-29 05:50 UTCEG score recompute
  3. 2026-08-28 21:42 UTCEPSS rescore
  4. 2026-08-28 04:46 UTCEG score recompute
  5. 2026-08-27 03:42 UTCEG score recompute
  6. 2026-08-26 14:47 UTCEPSS rescore
  7. 2026-08-26 02:39 UTCEG score recompute
  8. 2026-08-25 13:49 UTCEPSS rescore
  9. 2026-08-25 01:35 UTCEG score recompute
  10. 2026-08-24 00:32 UTCEG score recompute
  11. 2026-08-23 00:19 UTCEPSS rescore
  12. 2026-08-22 23:29 UTCEG score recompute
  13. 2026-08-21 23:49 UTCEPSS rescore
  14. 2026-08-21 22:25 UTCEG score recompute
  15. 2026-08-21 21:52 UTCEG score recompute
  16. 2026-08-20 21:17 UTCEG score recompute
  17. 2026-08-20 21:16 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-67445?
CVE-2026-67445 is a medium vulnerability published on August 20, 2026. Mailpit is an email testing tool and API for developers. Prior to 1.30.4, Mailpit reads SMTP commands through internal/smtpd/smtpd.go session.readLine() using bufio.Reader.ReadString before session.parseLine() parses the verb or the RFC 5321 512-octet command-line limit is enforced. An…
When was CVE-2026-67445 disclosed?
CVE-2026-67445 was first published in the National Vulnerability Database on August 20, 2026, with the most recent update on August 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-67445 actively exploited?
CVE-2026-67445 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 70.1% of all scored CVEs.
What is the CVSS score of CVE-2026-67445?
CVE-2026-67445 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-67445?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-67445, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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