CVE-2026-127121
SOGo before 5.12.13 S/MIME Certificate Spoofing via UIxMailView
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- None
What each source reports
CVE List Score used 7.1
SOGo before 5.12.13 S/MIME Certificate Spoofing via UIxMailView
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.
- Record
CVE-2026-127121- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N - Weakness
- CWE-347
- Updated
- 2026-11-12
EUVDEUVD-2026-124529 7.1
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.
- Record
EUVD-2026-124529- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-12
GitHub AdvisoriesGHSA-5qq6-8vww-hwx8 7.1
SOGo before 5.12.13 contains an improper cryptographic signature verification vulnerability that...
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.
- Record
GHSA-5qq6-8vww-hwx8- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N - Weakness
- CWE-347
- Updated
- 2026-11-12
NVD 7.1
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.
- Record
CVE-2026-127121- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N - Weakness
- CWE-347
- Updated
- 2026-11-12
OSV 7.1
SOGo before 5.12.13 S/MIME Certificate Spoofing via UIxMailView
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.
- Record
CVE-2026-127121- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-347
- Updated
- 2026-11-13
OSVDEBIAN-CVE-2026-127121 7.1
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.
- Record
DEBIAN-CVE-2026-127121- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Updated
- 2026-11-13
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
sogoDebian:12 | All versions, plus listed versions 5.10.0-15.10.0-25.10.0-35.11.0-15.11.0-2 Show 32 moreShow less5.11.1-15.11.2-15.11.2-25.11.2-35.11.2-45.12.0-15.12.1-15.12.1-25.12.1-35.12.10-15.12.11-15.12.12-15.12.13-15.12.3-15.12.3-25.12.4-15.12.4-1.15.12.4-1.25.12.6-15.12.7-15.12.8-15.12.8-25.12.9-15.8.0-15.8.0-2+deb12u15.8.0-2+deb12u25.8.0-2+deb12u35.8.2-15.8.3-15.8.4-15.9.0-15.9.1-1 | None known |
sogoDebian:13 | All versions, plus listed versions 5.12.1-35.12.1-3+deb13u15.12.1-3+deb13u25.12.1-3+deb13u35.12.10-1 Show 13 moreShow less5.12.11-15.12.12-15.12.13-15.12.3-15.12.3-25.12.4-15.12.4-1.15.12.4-1.25.12.6-15.12.7-15.12.8-15.12.8-25.12.9-1 | None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| references | OSV | |
| affected, aliases, references | OSV | |
| published | EUVD | |
| published | EUVD | |
| aliases, references | GitHub Advisories, NVD | |
| aliases, products, published | EUVD, NVD | |
| first indexed | CVE List |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-127121 is a high vulnerability (CVSS 7.1) in Alinto Sogo, published November 12, 2026. No source lists public exploit code. No source names a fixed version.
References
github.com/Alinto/sogo/releases/tag/SOGo-5.12.13
vulncheck.com/advisories/sogo-before-s-mime-certificate-spoofing-via-uixmailview
nvd.nist.gov/vuln/detail/CVE-2026-127121
github.com/advisories/GHSA-5qq6-8vww-hwx8
github.com/Alinto/sogo
github.com/CVEProject/cvelistV5/tree/main/cves/2026/127xxx/CVE-2026-127121.json
security-tracker.debian.org/tracker/CVE-2026-127121