Skip to content
Sign in
CVE-2026-936317.1High

Zimbra Collaboration Suite OAuth Extension Cross-Site Request Forgery Enables Account Linking

Zimbra · Zimbra Collaboration Suite

Not in CISA KEVVendor fix available
0.1%probability of exploitation in the next 30 days
3rd percentile
050100

Higher than 3% of scored CVEs

7.1HighCVSS
LowHigh

DescriptionNVD

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.

Coverage1 article · 1 outlet

First in our coverage: SecurityOnline, 27 Oct.

  1. Rapid7 Discloses 17 Flaws in Zimbra Collaboration Suite
    SecurityOnline · first in our coverage · mentions it in passing

New articles also arrive in the RSS feed.

References

Updated AboutDevelopersSign in