common/session.c in Claws Mail before 3.17.6 has a protocol violation because suffix data after STARTTLS is mishandled.
Priority MEDIUM 47Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA.
Summary
common/session.c in Claws Mail before 3.17.6 has a protocol violation because suffix data after STARTTLS is mishandled.
Why it matters now
EPSS 0.02614 85th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:claws-mail:claws-mail:*:*:*:*:*:*:*:* | before 3.17.6 | Vulnerable | Claws Mail |
| cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:* | 31 | Vulnerable | Fedoraproject |
| cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* | 32 | Vulnerable | Fedoraproject |
| cpe:2.3:a:opensuse:backports_sle:15.0:sp1:*:*:*:*:*:* | 15.0 sp1 | Vulnerable | openSUSE |
| cpe:2.3:a:opensuse:backports_sle:15.0:sp2:*:*:*:*:*:* | 15.0 sp2 | Vulnerable | openSUSE |
| cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:* | 15.1 | Vulnerable | openSUSE |
| cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:* | 15.2 | Vulnerable | openSUSE |
- cpe:2.3:a:claws-mail:claws-mail:*:*:*:*:*:*:*:* Versions before 3.17.6 Vulnerable ·Claws Mail
- cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:* Versions 31 Vulnerable ·Fedoraproject
- cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* Versions 32 Vulnerable ·Fedoraproject
- cpe:2.3:a:opensuse:backports_sle:15.0:sp1:*:*:*:*:*:* Versions 15.0 sp1 Vulnerable ·openSUSE
- cpe:2.3:a:opensuse:backports_sle:15.0:sp2:*:*:*:*:*:* Versions 15.0 sp2 Vulnerable ·openSUSE
- cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:* Versions 15.1 Vulnerable ·openSUSE
- cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:* Versions 15.2 Vulnerable ·openSUSE
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2020-15917
- 2026-10-03 Alias added: GHSA-9rxj-vjg6-w53x
References
Advisory 8
Sources
- CVE-2020-15917 · CVE Program
- CVE-2020-15917 · NVD
- FIRST EPSS
- GHSA-9rxj-vjg6-w53x · GitHub Advisory Database · CC BY 4.0
- CVE-2020-15917 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences