core · Hubzilla 11.2.1 contains a cross-site request forgery vulnerability in the OAuth2 /authorize endpoint handled by Zotlabs\Module\Authorize::post() that allows unauthenticated attackers to register arbitrary OAuth2 applications under an authenticated user's account by submitting a cross-origin POST request without CSRF token or Origin/Referer validation
Affects coreSource GCVE Database
Not known to be exploited · CVSS 4.3 Medium.
Data as of 5 Nov 2026, 23:24 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 6 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
GitHubhubzilla/corepkg:github/hubzilla/coreOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until a fix is available, users should be cautious about cross-origin requests and consider implementing additional CSRF protections or monitoring OAuth2 application registrations if possible.
Description
Hubzilla 11.2.1 contains a cross-site request forgery vulnerability in the OAuth2 /authorize endpoint handled by Zotlabs\Module\Authorize::post() that allows unauthenticated attackers to register arbitrary OAuth2 applications under an authenticated user's account by submitting a cross-origin POST request without CSRF token or Origin/Referer validation. Attackers can craft a malicious HTML form that autosubmits attacker-chosen OAuth2 parameters including client_id, client_secret, redirect_uri, and scope to silently register a persistent OAuth2 application, enabling interception of future OAuth2 authorization codes when the victim later authenticates against the attacker-controlled client.
References
- nvd.nist.gov/vuln/detail/CVE-2026-70556 (opens in a new tab)
- framagit.org/hubzilla/core (opens in a new tab)
- framagit.org/hubzilla/core/-/blob/dev/Zotlabs/Module/Authorize.php?ref_type=heads (opens in a new tab)
- hub.volse.no/cloud/harald/Skjermopptak_20260616_095037.webm (opens in a new tab)
- vulncheck.com/advisories/hubzilla-csrf-via-oauth2-authorize-endpoint-app-registration (opens in a new tab)