Apache ZooKeeper is widely used in distributed systems; authenticated clients can impersonate any SASL identity, including superuser, enabling full data-tree compromise.
CVE-2026-100252
Auth bypass in Apache ZooKeeper allows SASL identity spoofing and potential full data-tree takeover.
Is CVE-2026-100252 being exploited?
Not confirmed. CVE-2026-100252 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked.
How severe is CVE-2026-100252?
CVE-2026-100252 is rated High with a CVSS score of 8.6. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-100252?
Yes. A fix has been recorded for CVE-2026-100252. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-100252 affect?
CVE-2026-100252 affects Apache ZooKeeper 3.8.x (<3.8.8), Apache ZooKeeper 3.9.x (<3.9.7), ZooKeeper clusters with SASL auth enabled. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-100252?
Upgrade to 3.8.8 or 3.9.7 immediately; restrict SASL client access and review ACLs.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated SASL client can claim arbitrary authzid, bypass ACLs, and gain superuser/full data-tree access.
Immediate action required
- affected>= 3.9.0 and <= 3.9.6
- affected>= 3.8.0 and <= 3.8.7
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
cisa ssvc
- exploitation
- none
- automatable
- no
- technical impact
- total
Assessed by CISA 4 Nov 2026 (SSVC 2.0.3).
timeline
- 4 Nov 2026CISA SSVC assessment: exploitation none
- 4 Nov 2026Published · same day later
- 5 Nov 2026CVE record last updated · 1 day later
- 5 Nov 2026Analysed by vulneraibility.com · same day later
- Advisorylists.apache.org /thread.html/81rdyqlmlp3dtkkqgp8t5080g3b9r2pj
- Linkopenwall.com /lists/oss-security/2026/11/03/10
sources
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.