---
cve: "CVE-2026-42246"
severity: "HIGH"
cvss: 7.6
epss: "31%"
vendor: "Ruby"
kev: false
exploited: false
published: "2026-05-09 20:16:28"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-08T16:20:38+02:00"
---

# CVE-2026-42246

> 7.6 HIGH · 🧪 PoC

## Beschreibung

Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4, a man-in-the-middle attacker can cause Net::IMAP#starttls to return "successfully", without starting TLS. This issue has been patched in versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |

## Patch verfügbar (OSV)

- ec89812d3c986d6394d3bc0b93048e704aec6af9 (Commit)
- 24a4e770b43230286a05aa2a9746cdbb3eb8485e (Commit)

## Referenzen

- <https://github.com/ruby/net-imap/security/advisories/GHSA-vcgp-9326-pqcp>
- <https://github.com/ruby/net-imap/commit/0ede4c40b1523dfeaf95777b2678e54cc0fd9618>
- <https://github.com/ruby/net-imap/commit/24a4e770b43230286a05aa2a9746cdbb3eb8485e>
- <https://github.com/ruby/net-imap/commit/97e2488fb5401a1783bddd959dde007d9fbce42c>
- <https://github.com/ruby/net-imap/commit/f79d35bf5833f186e81044c57c843eda30c873da>
- <https://github.com/ruby/net-imap/releases/tag/v0.3.10>
- <https://github.com/ruby/net-imap/releases/tag/v0.4.24>
- <https://github.com/ruby/net-imap/releases/tag/v0.5.14>
- <https://access.redhat.com/errata/RHSA-2026:33462>
- <https://access.redhat.com/errata/RHSA-2026:33512>
- <https://access.redhat.com/errata/RHSA-2026:33514>
- <https://access.redhat.com/errata/RHSA-2026:33515>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-42246) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_