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Fencer Vulns
high 8.6

CVE-2026-100252 json

Apache ZooKeeper: SASL authorization bypass on the client port through a client-supplied authorization ID

published 2026-11-04 5 d ago modified 2026-11-05 4 d ago also EUVD-2026-116867

cvss
8.6
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits
0
none known

Summary

Improper Authorization vulnerability in Apache ZooKeeper.

When SASL authentication is enabled on the client port, the server's SASL callback handler grants every authorization identity (authzid) that a client requests, without checking it against the principal the client authenticated as. The server then tries to replace the requested identity with a canonical form of the authenticated principal, derived from the zookeeper.security.auth_to_local rules. If no rule applies to the principal, canonicalization fails and the error is only logged. The client-requested authzid then becomes the session's SASL identity for all ACL checks.

An authenticated client whose principal is not covered by the auth_to_local rules can therefore claim any SASL identity. With the default rules, this includes any Kerberos principal from a realm other than the server's default realm, such as a principal from a cross-realm trusted realm. The client then gets the permissions granted to that identity in sasl ACLs. If the requested identity matches a configured zookeeper.superUser, it gets superuser access to the whole data tree.

Users are recommended to upgrade to version 3.8.8 or 3.9.7, which fixes the issue.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-100252 updated cvss 8.1

org.apache.zookeeper/zookeeper: zookeeper: Privilege escalation via improper SASL authorization identity validation

  • Red Hat AMQ Broker 7 zookeeper 3.9.5.redhat-00001
    affected: workaround, no fix available
  • Red Hat Fuse 7 zookeeper 3.9.5.redhat-00001
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Offline Knowledge Portal offline-knowledge-portal/rhokp-rhel9 Red Hat OpenShift AI (RHOAI) rhoai/odh-modelmesh-rhel9, rhoai/odh-spark-operator-rhel9
    affected: workaround, no fix available
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-th-torch-cpu-py312-rhel9, rhoai/odh-th-torch-cuda-py312-rhel9, rhoai/odh-th06-cpu-torch210-py312-rhel9, rhoai/odh-th06-cpu-torch291-py312-rhel9, rhoai/odh-th06-rocm64-torch291-py312-rhel9, rhoai/odh-th06-cuda130-torch210-py312-rhel9, +1 more
    not affected: vulnerable code not in execute path

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
5 d ago

Exploit prediction

0.53% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 8.6 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CNA 4.0 8.6 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • Apache Software Foundation Apache ZooKeeper

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.