CVE-2026-100235
| Severity | 6.0 Medium CVSS 4.0 |
|---|---|
| Weakness | CWE-367 |
| Published | 4 Nov 2026 |
| Updated | 5 Nov 2026 |
Published 10 days ago. NVD often adds the list of affected products days or weeks after a CVE is published, and the other sources we check lag too. The scope and status here may change.
Description
Incorrect authorization due to a time-of-check to time-of-use (TOCTOU) race condition in the setACL request handling of Apache ZooKeeper. When a node's ACL is changed via setACL, the pending change is not published to the server's outstanding change record for that node. Any request that is prepared (and authorized) after the setACL is submitted but before it commits is therefore checked against the previous, pre-revocation ACL, yet is applied to the data tree after the ACL change has taken effect. A client that currently holds a permission can use this window to perform operations requiring that permission through and after its revocation — for example, committing writes or deletes after losing write access, or re-granting itself full permissions, which persistently defeats the revocation. In deployments transitioning from the default OPEN_ACL_UNSAFE ACL to a restrictive ACL, any unauthenticated client can exploit this during the transition. This issue affects Apache ZooKeeper up to and including 3.9.6. Users are recommended to upgrade to version 3.8.8 or 3.9.7, which fixes the issue.
Exploitation status
No public exploit
No exploit has been reported in the sources we check.
Exploitation status
- CISA KEV not listed
- VulnCheck KEV not listed
- CISA Vulnrichment exploitation: none
- Indexed PoC none indexed
- EPSS 0.34% chance in 30 days
Waratek protection
Within Waratek scope. In the sources we check, nobody has published exploit code for this CVE or reported it being exploited.
VRT has not found a public code change for this CVE yet.
- Protection none
- Action not pursued
- Review automated Upstream data
- Record active
| Decided by | Nothing to build a rule from yet: no published exploit, no CISA record of exploitation and no source-level change to read |
|---|---|
| Finding | This CVE affects a known product, but nothing published names a fix and nothing published shows an exploit. That is a statement about the evidence, not about the defect — it does not mean the vulnerability is unimportant or unreachable, only that neither of the two things VRT can act on exists. |
References
| URL | Tags |
|---|---|
| https://lists.apache.org/thread.html/r40gp594o64mycwybc3v9dtvrm0vos0l | |
| http://www.openwall.com/lists/oss-security/2026/11/03/9 |
Timeline
Timeline
| Published | 2026-11-04 | By the CVE Program. |
|---|---|---|
| NVD record modified | 2026-11-05 | NVD's own last-modified date for this record. |