CVE-2026-123497 PUBLISHED

Vikunja veans before 2.7.1 HTTPS to HTTP Downgrade in Server Discovery

Assigner: VulnCheck
Reserved: 06.11.2026 Published: 08.11.2026 Updated: 08.11.2026

Vikunja veans before 2.7.1 contains a protocol downgrade vulnerability in serverCandidates that allows on-path attackers to force plain HTTP during veans init and login. Attackers can block HTTPS ports so discovery accepts an unverified HTTP response, capturing passwords, TOTP codes or bot tokens and persisting cleartext API traffic.

CVSS Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CVSS Score: 7.6

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	High	Integrity	High	Integrity	None
Attack Requirements	Present	Availability	None	Availability	None
Privileges Required	None
User Interaction	Passive

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
CVSS Score: 6.8

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	High
Privileges Required	None	Integrity Impact	High
User Interaction	Required	Availability Impact	None

CVSS 3.1

Product Status

Vendor	go-vikunja
Product	vikunja
Versions	Default: unaffected affected from 0 to 2.7.1 (excl.) Version 2.7.1 is unaffected

References

Problem Types

Cleartext Transmission of Sensitive Information CWE