fedify-dev hollo up to 0.6.19/0.7.1/0.7.1 ActivityPub Outbox Endpoint authorization

Summaryinfo

A vulnerability was found in fedify-dev hollo up to 0.6.19/0.7.1/0.7.1. It has been classified as problematic. The impacted element is an unknown function of the component ActivityPub Outbox Endpoint. The manipulation leads to authorization. This vulnerability is uniquely identified as CVE-2026-25808. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in fedify-dev hollo up to 0.6.19/0.7.1/0.7.1. It has been rated as problematic. This issue affects an unknown code block of the component ActivityPub Outbox Endpoint. The manipulation with an unknown input leads to a authorization vulnerability. Using CWE to declare the problem leads to CWE-862. The product does not perform an authorization check when an actor attempts to access a resource or perform an action. Impacted is confidentiality. The summary by CVE is:

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.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-25808 since 02/05/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available.

Upgrading to version 0.6.20, 0.7.2 or 0.7.2 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 329969c502ef092d5c3f9c2c20421c34f4ff0f0e is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• fedify-dev

Name

• hollo

Version

• 0.6.0
• 0.6.1
• 0.6.2
• 0.6.3
• 0.6.4
• 0.6.5
• 0.6.6
• 0.6.7
• 0.6.8
• 0.6.9
• 0.6.10
• 0.6.11
• 0.6.12
• 0.6.13
• 0.6.14
• 0.6.15
• 0.6.16
• 0.6.17
• 0.6.18
• 0.6.19
• 0.7.0
• 0.7.1

License

• open-source

Website

• Product: https://github.com/fedify-dev/hollo/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion