Security readout for executives and security teams
Plain-English summary
Discourse sites using the Patreon plugin may accept forged Patreon webhook messages if the webhook secret is left blank. An unauthenticated attacker could alter Patreon pledge data or trigger group synchronization. This is a business-risk issue where Patreon-based access, membership, or community entitlements depend on Discourse group mapping.
Executive priority
Prioritize remediation for any Discourse community where Patreon pledges control access, roles, or paid membership benefits. The issue can affect entitlement integrity without requiring attacker credentials.
Technical view
Before Discourse 2025.12.2, 2026.1.1, and 2026.2.0, a blank `patreon_webhook_secret` allows valid webhook signatures to be forged using HMAC-MD5 with an empty key. Because the sender controls the request body, arbitrary webhook payloads can pass validation, enabling unauthorized creation, modification, or deletion of Patreon pledge data and patron-to-group sync actions.
Likely exposure
Exposure is likely limited to Discourse deployments using the Patreon plugin webhook endpoint where `patreon_webhook_secret` is blank and the instance runs an affected version. Internet-reachable Discourse sites are at higher risk because the issue requires no authentication or user interaction.
Exploitation context
The CVSS vector is network-accessible, low complexity, no privileges, and no user interaction, with high integrity impact. The provided sources do not report active exploitation, and the CVE is not marked KEV in the supplied bundle.
Researcher notes
The vulnerability depends on unsafe acceptance of webhook signatures when the shared secret is unset. The fix rejects webhook requests if the secret is not configured. Evidence is limited to the CVE record and GitHub advisory; no public exploitation evidence is provided in the bundle.
Mitigation direction
- Upgrade Discourse to 2025.12.2, 2026.1.1, 2026.2.0, or later applicable release.
- Configure `patreon_webhook_secret` with a strong, non-empty secret value.
- Review vendor advisory for deployment-specific upgrade and configuration guidance.
Validation and detection
- Confirm the running Discourse version is not in the affected ranges.
- Check whether the Patreon plugin webhook endpoint is enabled or configured.
- Verify `patreon_webhook_secret` is set to a strong, non-empty value.
- Review recent Patreon webhook activity for unexpected pledge or group changes.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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CWE-639: Exact CWE lookup
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Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-26078 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/discourse/discourse/security/advisories/GHSA-frx4-wg35-4r68CVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Authorization Bypass Through User-Controlled Key
Authorization Bypass Through User-Controlled Key represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.