How serious is CVE-2026-26078?

This vulnerability has a CVSS score of 7.5 out of 10, classified as HIGH severity. No public exploit code has been identified yet.

Which products are affected by CVE-2026-26078?

CVE-2026-26078 affects discourse discourse. Check the full CVE details for specific version information.

How do I fix CVE-2026-26078?

To remediate CVE-2026-26078, check for security patches from discourse. Apply all available updates and security patches. If no patch is available, implement recommended workarounds or security controls to mitigate the risk.

CVE-2026-26078

High

|7.5

No Exploit

Plain English Summary

AI-powered analysis for quick understanding

An attacker can send fake webhook messages to a Discourse site, allowing them to create, change, or delete Patreon pledge data if the site's webhook secret is left blank. To prevent this, it's crucial to set a strong, non-empty webhook secret in the site settings.

Technical Description

Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, when the `patreon_webhook_secret` site setting is blank, an attacker can forge valid webhook signatures by computing an HMAC-MD5 with an empty string as the key. Since the request body is known to the sender, the attacker can produce a matching signature and send arbitrary webhook payloads. This allows unauthorized creation, modification, or deletion of Patreon pledge data and triggering patron-to-group synchronization. This vulnerability is patched in versions 2025.12.2, 2026.1.1, and 2026.2.0. The fix rejects webhook requests when the webhook secret is not configured, preventing signature forgery with an empty key. As a workaround, configure the `patreon_webhook_secret` site setting with a strong, non-empty secret value. When the secret is non-empty, an attacker cannot forge valid signatures without knowing the secret.

CVSS Vector Analysis

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

Confidentiality ImpactNone

Integrity ImpactHigh

Availability ImpactNone

ScopeUnchanged

Vector String

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Exploit Resources

Search for proof-of-concept code and exploit modules

GitHub Search Exploit-DB Nuclei Templates Metasploit Vulners

Official References

NIST NVD

Est. Bounty

$2,053($1K-$5K)

Vendor Response

Grade APatched in 4 days

Quick Information

Published

Feb 26, 2026

about 1 month ago

Last Modified

Mar 2, 2026

about 1 month ago

Vendor

discourse

Product

discourse

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This vulnerability allows an attacker to access private user information, such as phone numbers and addresses, from all users in a Discourse forum, even if they are not logged in. It occurs because the system does not properly check permissions for certain user data fields, making it easy for anyone to exploit this flaw and collect sensitive information.

CVE-2026-26207Medium

This vulnerability allows any authenticated user to manipulate policies on posts they shouldn't be able to access, including private posts, and to discover which posts have policies based on error messages. It affects users of the discourse platform who have the `discourse-policy` plugin enabled and can be fixed by upgrading to the latest versions or disabling the plugin altogether.

CVE-2026-26077Medium

This vulnerability allows attackers to send fake data to certain email service integrations on the Discourse platform, which can lead to legitimate user emails being mistakenly marked as undeliverable. It occurs when no authentication token is set up, meaning attackers can exploit this weakness without needing any special access.