CVE-2026-127121
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in, but needs a user to act. High risk of data tampering.
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- ReservedThe CVE id was reserved by its CNA
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: not scored yet.
- Severity: 7.1 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Weakness
- CWE-347
- Record status
- Deferred
Attack profile CVSS 4.0 · 7.1
- Attack vector
- Network
- Complexity
- Low
- Attack requirements
- None
- Privileges needed
- None
- User interaction
- Passive
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Raw vector
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
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-127121.md and follow it. Check whether this project is affected by CVE-2026-127121. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
