Auth bypass in Fedify Hollo
CVE-2026-25808
Hollo is a federated single-user microblogging software designed to be federated through ActivityPub. Prior to 0.6.20 and 0.7.2, there is a security vulnerability where DMs and followers-only posts were exposed through the ActivityPub outbox endpoint without authorization. This vulnerability is fixed in 0.6.20 and 0.7.2.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.005 (42.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 42.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001
Affected products
- Fedify Hollo
- Fedify-Dev Hollo — versions < 0.6.20, 0.7.2, >= 7.0.0, < 0.7.2
Weakness classification (CWE)
References
- github.com/fedify-dev/hollo/security/advisories/GHSA-6r2w-3pcj-v4v5 (Exploit, Vendor Advisory)
- github.com/fedify-dev/hollo/commit/329969c502ef092d5c3f9c2c20421c34f4ff0f0e (Patch)
- github.com/fedify-dev/hollo/releases/tag/0.6.20 (Product, Release Notes)
- github.com/fedify-dev/hollo/releases/tag/0.7.2 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-25808?
- CVE-2026-25808 is a high-severity vulnerability in Fedify Hollo, classified under Missing Authorization. CVSS score: 7.5/10. Published 2026-02-09.
- How severe is CVE-2026-25808?
- High severity. CVSS v3 base score is 7.5 out of 10.