Security Flaw in Hollo Microblogging Software Exposes Private Messages
CVE-2026-25808

7.5HIGH

Key Information:

Vendor

Fedify-dev

Status
Hollo
Vendor
CVE Published:
9 February 2026

What is CVE-2026-25808?

Hollo, a federated single-user microblogging platform, has a vulnerability that allows unauthorized access to direct messages and followers-only content via the ActivityPub outbox endpoint in versions prior to 0.6.20 and 0.7.2. This security flaw compromises user privacy and exposes sensitive information, necessitating immediate updates to secure affected systems.

Affected Version(s)

hollo < 0.6.20, 0.7.2 < 0.6.20, 0.7.2

hollo >= 7.0.0, < 0.7.2 < 7.0.0, 0.7.2

References

https://github.com/fedify-dev/hollo/security/advisories/G...
x_refsource_CONFIRM
https://github.com/fedify-dev/hollo/commit/329969c502ef09...
x_refsource_MISC
https://github.com/fedify-dev/hollo/releases/tag/0.6.20
x_refsource_MISC

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.