Introducing #Hollo. Hollo is an #ActivityPub-enabled single-user microblogging software. Although it's for a single user, it also supports creating and running multiple accounts for different topics.

It's headless, meaning you can use existing #Mastodon client apps instead, with its Mastodon-compatible APIs. It has most feature parity with Mastodon. Two big differences with Mastodon is that you can use #Markdown in the content of your posts and you can quote another post.

Oh, and Hollo is built using #Bun and #Fedify.

https://github.com/dahlia/hollo

#fedidev

Security update: Hollo 0.6.12 is now available

We've released #Hollo 0.6.12 to fix a critical privacy #vulnerability where direct messages were being exposed in the replies section of public posts. Please update your instances immediately to ensure your private conversations remain private.

#security

New compatibility table at funfedi.dev: JSON-LD @context

https://funfedi.dev/support_tables/generated/context/

6 out of 9 implementations accept any @context value. But Mastodon, Hollo and Friendica reject activity entirely if https://www.w3.org/ns/activitystreams is not included in @context. Mastodon probably does this for no reason, but what about #Friendica and #Hollo?

#ActivityPub specification, section 3. Objects:

Implementers SHOULD include the ActivityPub context in their object definitions. Implementers MAY include additional context as appropriate.

ActivityPub context is recommended, but not required.

New compatibility table at funfedi.dev: JSON-LD @context

https://funfedi.dev/support_tables/generated/context/

6 out of 9 implementations accept any @context value. But Mastodon, Hollo and Friendica reject activity entirely if https://www.w3.org/ns/activitystreams is not included in @context. Mastodon probably does this for no reason, but what about #Friendica and #Hollo?

#ActivityPub specification, section 3. Objects:

Implementers SHOULD include the ActivityPub context in their object definitions. Implementers MAY include additional context as appropriate.

ActivityPub context is recommended, but not required.

We've released #security updates for #Hollo (0.4.12, 0.5.7, and 0.6.6) to address a #vulnerability in the underlying #Fedify framework. These updates incorporate the latest Fedify security patches that fix CVE-2025-54888.

We strongly recommend all Hollo instance administrators update to the latest version for their respective release branch as soon as possible.

Update Instructions:

• Railway users: Go to your project dashboard, select your Hollo service, click the three dots menu in deployments, and choose “Redeploy”
• Docker users: Pull the latest image with docker pull ghcr.io/fedify-dev/hollo:latest and restart your containers
• Manual installations: Run git pull to get the latest code, then pnpm install and restart your service

We've released #security updates for #Hollo (0.4.12, 0.5.7, and 0.6.6) to address a #vulnerability in the underlying #Fedify framework. These updates incorporate the latest Fedify security patches that fix CVE-2025-54888.

We strongly recommend all Hollo instance administrators update to the latest version for their respective release branch as soon as possible.

Update Instructions:

• Railway users: Go to your project dashboard, select your Hollo service, click the three dots menu in deployments, and choose “Redeploy”
• Docker users: Pull the latest image with docker pull ghcr.io/fedify-dev/hollo:latest and restart your containers
• Manual installations: Run git pull to get the latest code, then pnpm install and restart your service

🚨 Security Update: Hollo 0.6.5 Released

We've released #Hollo 0.6.5 with a critical #security fix for CVE-2025-53941, addressing an HTML injection vulnerability in federated posts.

Please #update immediately to protect your instance from potential phishing and XSS attacks.

How to update:

• Railway: Go to deployments → click three dots → Redeploy
• Docker: docker pull ghcr.io/fedify-dev/hollo:latest and restart
• Manual: git pull origin stable && pnpm install and restart server

🚨 Security Update: Hollo 0.6.5 Released

We've released #Hollo 0.6.5 with a critical #security fix for CVE-2025-53941, addressing an HTML injection vulnerability in federated posts.

Please #update immediately to protect your instance from potential phishing and XSS attacks.

How to update:

• Railway: Go to deployments → click three dots → Redeploy
• Docker: docker pull ghcr.io/fedify-dev/hollo:latest and restart
• Manual: git pull origin stable && pnpm install and restart server

Exciting news for the #Hollo project! We're thrilled to announce that Emelia Smith ( @thisismissem) has joined as a co-maintainer alongside Hong Minhee ( @hongminhee).

Emelia brings extensive experience in the #fediverse ecosystem, having been a long-time contributor to Mastodon and a leading expert in trust & safety tooling for decentralized social networks. She's dedicated years to improving moderation systems and security across #ActivityPub platforms.

Her recent contributions to Hollo have been substantial—implementing the reporting/flagging system and making significant improvements to OAuth and security features. These valuable contributions naturally led to her joining as a co-maintainer.

This collaboration marks an important milestone for Hollo as we continue building better single-user microblogging software for the fediverse. Welcome aboard, Emelia! 🚀

Exciting news for the #Hollo project! We're thrilled to announce that Emelia Smith ( @thisismissem) has joined as a co-maintainer alongside Hong Minhee ( @hongminhee).

Emelia brings extensive experience in the #fediverse ecosystem, having been a long-time contributor to Mastodon and a leading expert in trust & safety tooling for decentralized social networks. She's dedicated years to improving moderation systems and security across #ActivityPub platforms.

Her recent contributions to Hollo have been substantial—implementing the reporting/flagging system and making significant improvements to OAuth and security features. These valuable contributions naturally led to her joining as a co-maintainer.

This collaboration marks an important milestone for Hollo as we continue building better single-user microblogging software for the fediverse. Welcome aboard, Emelia! 🚀

Exciting news for the #Hollo project! We're thrilled to announce that Emelia Smith ( @thisismissem) has joined as a co-maintainer alongside Hong Minhee ( @hongminhee).

Emelia brings extensive experience in the #fediverse ecosystem, having been a long-time contributor to Mastodon and a leading expert in trust & safety tooling for decentralized social networks. She's dedicated years to improving moderation systems and security across #ActivityPub platforms.

Her recent contributions to Hollo have been substantial—implementing the reporting/flagging system and making significant improvements to OAuth and security features. These valuable contributions naturally led to her joining as a co-maintainer.

This collaboration marks an important milestone for Hollo as we continue building better single-user microblogging software for the fediverse. Welcome aboard, Emelia! 🚀