CVSS 4.0
7.1 highCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:NCVE-2026-127121 SOGo before 5.12.13 S/MIME Certificate Spoofing via UIxMailView
High (7.1) in alinto sogo. EPSS 0.1% estimated probability of exploitation activity in the next 30 days.
On this page
SOGo before 5.12.13 contains an improper cryptographic signature verification vulnerability that allows remote attackers to replace a victim's contact S/MIME certificate by sending a spoofed multipart/signed message with a mismatched signature and an impersonated From address. Attackers can deliver a crafted CMS signedData object containing their own self-signed certificate, which SOGo's UIxMailView stores on the contact card without validating signature authenticity or certificate identity, enabling subsequent encrypted communications to be decrypted with the attacker's private key.
Severity
CVSS 3.1
6.5 mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N- EPSS
- 0.1% estimated probability of exploitation activity in the next 30 days; 4th percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: none · Automatable: yes · Technical impact: partial, assessed 2026-11-12. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-347 Improper Verification of Cryptographic Signature
- OWASP Top 10
- A04:2025 Cryptographic Failures
- Published
- Modified
- Assigned by
- VulnCheck (CNA)
- NVD analysis
- Deferred: the NVD does not plan to analyze it
- Record from
- the NVD, synced
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Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| Alinto sogo | before 5.12.13 |
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Debian | 12, 13 | sogo | no fix listed | DEBIAN-CVE-2026-127121 |
| Ubuntu | 26.10, Pro:16.04:LTS, Pro:18.04:LTS and 3 more | sogo | no fix listed | UBUNTU-CVE-2026-127121 |
From the distributions' data via OSV.dev: the Debian Security Tracker; Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Debian · Ubuntu.
Attack patterns (CAPEC)
- CAPEC-463 Padding Oracle Crypto Attack Severity: High
- CAPEC-475 Signature Spoofing by Improper Validation Likelihood: Low · Severity: High
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.
History
- The NVD deferred its analysis
Changes since this site first stored the record. The same for every record: /api/public/changes.