CVE-2026-93631 json
Zimbra Collaboration Suite OAuth Extension Cross-Site Request Forgery Enables Account Linking
published 2026-10-23 17 d ago modified 2026-10-28 11 d ago also EUVD-2026-108972
- cvss
- 7.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 7%
- public exploits
- 0
- none known
Summary
A cross-site request forgery vulnerability in the OAuth extension of Zimbra Collaboration Suite (ZCS) Network Edition allows an attacker to link an attacker-controlled external account to a victim's mailbox. The OAuth callback does not bind its state value or authorization code to the initiating Zimbra session and instead selects the destination mailbox from the browser's current authentication cookie. On a deployment with the provider configured, an attacker can induce a signed-in victim to load a callback containing a fresh code for the attacker's provider account. This creates a persistent data source that imports attacker-controlled contacts or events. With bidirectional CalDAV synchronization, appointments subsequently created or edited in the linked calendar are also disclosed to the attacker. ZCS 10.1.16 and 10.1.20 are affected.
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 11 d ago
Exploit prediction
0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- rapid7.com https://www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries-part-1/ referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N |
Affected products
- Zimbra Zimbra Collaboration Suite
Classification
- Weakness
-
- CWE-352 Cross-Site Request Forgery
References
-
rapid7.com
/blog/post/ve-breaking-zimbra-identity-boundaries-part-1/
related, exploit, third-party-advisory
-
wiki.zimbra.com
/wiki/Zimbra_Security_Advisories
vendor-advisory
Sources
- CVE List CVE-2026-93631
- NVD CVE-2026-93631
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