CVE-2026-72723 Discourse: Anonymous sidebar serialization exposes descriptions of category-restricted tags

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, SiteSerializer.anonymousdefaultnavigationmenutags serializes tags from SiteSetting.defaultnavigationmenutags without applying DiscourseTagging.filtervisible for the anonymous viewer. An...

CVE-2026-72722

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, TopicLink.extractfrom, TopicLink.ensureentryfor, and TopicLink.duplicatelookup do not consistently enforce Guardian.cansee? checks when processing internal links. An authenticated user can submit...

CVE-2026-72722 Discourse: Duplicate lookup reveals restricted topic titles through canonicalized URLs

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, TopicLink.extractfrom, TopicLink.ensureentryfor, and TopicLink.duplicatelookup do not consistently enforce Guardian.cansee? checks when processing internal links. An authenticated user can submit...

EUVD-2026-55659

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, TopicLink.extractfrom, TopicLink.ensureentryfor, and TopicLink.duplicatelookup do not consistently enforce Guardian.cansee? checks when processing internal links. An authenticated user can submit...

CVE-2026-72722 Discourse: Duplicate lookup reveals restricted topic titles through canonicalized URLs

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, TopicLink.extractfrom, TopicLink.ensureentryfor, and TopicLink.duplicatelookup do not consistently enforce Guardian.cansee? checks when processing internal links. An authenticated user can submit...

CVE-2026-72722

Discourse (open‑source discussion platform) contains a vulnerability in TopicLink processing prior to versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0. The affected components are TopicLink.extract_from, TopicLink.ensure_entry_for, and TopicLink.duplicate_lookup. The root cause is that Guardia...

CVE-2026-72722 Discourse: Duplicate lookup reveals restricted topic titles through canonicalized URLs

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, TopicLink.extractfrom, TopicLink.ensureentryfor, and TopicLink.duplicatelookup do not consistently enforce Guardian.cansee? checks when processing internal links. An authenticated user can submit...

CVE-2026-72721 Discourse: Onebox Domain Blocklist Bypass via Case-Sensitive Comparison

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, Onebox::DomainChecker.isblocked? compares hostnames and SiteSetting.blockedoneboxdomains entries case-sensitively, allowing an attacker to bypass configured Onebox domain restrictions by changing...

CVE-2026-72721 Discourse: Onebox Domain Blocklist Bypass via Case-Sensitive Comparison

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, Onebox::DomainChecker.isblocked? compares hostnames and SiteSetting.blockedoneboxdomains entries case-sensitively, allowing an attacker to bypass configured Onebox domain restrictions by changing...

CVE-2026-72721 Discourse: Onebox Domain Blocklist Bypass via Case-Sensitive Comparison

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, Onebox::DomainChecker.isblocked? compares hostnames and SiteSetting.blockedoneboxdomains entries case-sensitively, allowing an attacker to bypass configured Onebox domain restrictions by changing...

CVE-2026-72721

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, Onebox::DomainChecker.isblocked? compares hostnames and SiteSetting.blockedoneboxdomains entries case-sensitively, allowing an attacker to bypass configured Onebox domain restrictions by changing...

CVE-2026-72721

Findings: CVE-2026-72721 affects Discourse prior to versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0. The root cause is a case-sensitive comparison in Onebox::DomainChecker.is_blocked?, which compares hostnames and SiteSetting.blocked_onebox_domains entries. This allows an attacker to bypass c...

EUVD-2026-55657

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, Onebox::DomainChecker.isblocked? compares hostnames and SiteSetting.blockedoneboxdomains entries case-sensitively, allowing an attacker to bypass configured Onebox domain restrictions by changing...

EUVD-2026-55656

Discourse is an open-source discussion platform. Prior to 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1, Discourse has HTML injection in PrettyText.formatforemail because cooked attribute values are reparsed as markup. Crafted Vimeo iframe sources, secure-upload URLs or dimensions, and...

CVE-2026-72720 Discourse: HTML injection in PrettyText.format_for_email from cooked-attribute reparsing

Discourse is an open-source discussion platform. Prior to 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1, Discourse has HTML injection in PrettyText.formatforemail because cooked attribute values are reparsed as markup. Crafted Vimeo iframe sources, secure-upload URLs or dimensions, and...

CVE-2026-72720 Discourse: HTML injection in PrettyText.format_for_email from cooked-attribute reparsing

Discourse is an open-source discussion platform. Prior to 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1, Discourse has HTML injection in PrettyText.formatforemail because cooked attribute values are reparsed as markup. Crafted Vimeo iframe sources, secure-upload URLs or dimensions, and...

CVE-2026-72720

CVE-2026-72720 affects the Discourse open‑source forum platform. The issue is an HTML injection vulnerability in PrettyText.format_for_email where cooked attribute values are reparsed as markup, enabling decoded attribute text from crafted Vimeo iframe sources, secure-upload URLs or dimensions, a...

CVE-2026-72720

Discourse is an open-source discussion platform. Prior to 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1, Discourse has HTML injection in PrettyText.formatforemail because cooked attribute values are reparsed as markup. Crafted Vimeo iframe sources, secure-upload URLs or dimensions, and...

CVE-2026-72720 Discourse: HTML injection in PrettyText.format_for_email from cooked-attribute reparsing

Discourse is an open-source discussion platform. Prior to 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1, Discourse has HTML injection in PrettyText.formatforemail because cooked attribute values are reparsed as markup. Crafted Vimeo iframe sources, secure-upload URLs or dimensions, and...

PT-2026-69864

Name of the Vulnerable Software and Affected Versions Discourse versions prior to 2026.1.6 Discourse versions prior to 2026.5.2 Discourse versions prior to 2026.6.1 Discourse versions prior to 2026.7.0 Description An authenticated user can obtain private thread message content by pairing a public...