The Apache Pulsar PMC published 14 security advisories for Apache Pulsar
on 21 October 2026 (1 critical, 4 high, 4 medium, 5 low). All of them
are fixed in Apache Pulsar 4.0.14, 4.2.5 and 5.0.0, and users are
recommended to upgrade:
- 4.0.14: https://lists.apache.org/thread/039cmmk4938zmqn2k8g8joqbpfmy1r1y
- 4.2.5: https://lists.apache.org/thread/x8v4r6kpyftzlphh3z18s6ywmrn66gxd
- 5.0.0: https://lists.apache.org/thread/ns4xjcz4cmnw778vljhbvd9zdf33867f
Each advisory was announced separately on [email protected]. Each
entry below gives the severity, the CVSS 4.0 base score, the affected
versions, a short summary and a link to the full announcement with the
description, CVSS vector and credit.
A separate message covers CVE-2026-105944 for Apache Pulsar Manager,
which has reached end of life.
CVE-2026-105869 (critical, CVSS 4.0 9.2)
Apache Pulsar: MultiRolesTokenAuthorizationProvider uses roles from
unverified tokens for HTTP requests that fall back to the anonymous user
role
In deployments that use MultiRolesTokenAuthorizationProvider with a
non-empty anonymousUserRole, HTTP and WebSocket requests whose
credentials fail authentication fall back to the anonymous user role,
and the provider then authorized them with the roles listed in the
unverified bearer token. An unauthenticated client could send a forged
or unsigned token and be authorized with any role, including a superuser
role.
Affected: 2.8.1 before 4.0.14; 4.1.0 before 4.2.5
https://lists.apache.org/thread/lf36z1tlcsokp4gv97obkdjtt74ngmrw
CVE-2026-105937 (high, CVSS 4.0 8.7)
Apache Pulsar: Missing authorization of the shadow topic source allows
cross-tenant message disclosure and deletion of source topic data
When creating a topic or updating topic properties, the broker did not
authorize the caller against the source topic named in the reserved
PULSAR.SHADOW_SOURCE property. A tenant admin of one tenant could bind a
shadow topic to a persistent topic in another tenant, read its messages
and delete source topic data.
Affected: 3.0.0 before 4.0.14; 4.1.0 before 4.2.5
https://lists.apache.org/thread/80foc311bwn839skc1p7fh89pgsrhyoj
CVE-2026-105942 (high, CVSS 4.0 7.7)
Apache Pulsar: Original principal of proxied requests authorized with
the proxy's authentication data, allowing privilege escalation
For requests sent by a proxy on behalf of another user, the broker
authorized the original principal with the proxy's authentication data,
so with MultiRolesTokenAuthorizationProvider the user gained the roles
in the proxy's token. Independently of the authorization provider, the
tenant admin check of a proxied admin REST API request passed without
checking the original principal when the proxy role was a tenant admin.
Affected: 2.8.1 before 4.0.14; 4.1.0 before 4.2.5
https://lists.apache.org/thread/4jmsbztr1fwws5fmxk36q5326wvjlwx4
CVE-2026-105945 (high, CVSS 4.0 7.7)
Apache Pulsar: Improper Validation of Package Name Components Allows
Cross-Tenant Package Access in Filesystem Package Storage
The version component of package names was not validated, so with the
filesystem package storage provider an authenticated user with the
packages permission on any namespace could download, overwrite or delete
packages stored in other tenants and namespaces.
Affected: 2.10.0 before 4.0.14; 4.1.0 before 4.2.5
https://lists.apache.org/thread/o5jt8zrg1qxqdrqlb06jjmj4lzydfm2k
CVE-2026-105934 (high, CVSS 4.0 7.2)
Apache Pulsar: Missing tenant admin authorization check when truncating
a partitioned topic
Truncating a partitioned topic through the admin REST API did not apply
the tenant admin check to the caller, and the broker truncated the
partitions with its own internal admin client. A user with only produce
or consume permission could permanently delete the messages of a
partitioned topic when the broker's internal identity is authorized for
the tenant.
Affected: 2.8.0 before 4.0.14; 4.1.0 before 4.2.5
https://lists.apache.org/thread/ox0vy41jlb41y2l04y7b6h2srlyqoj8o
CVE-2026-105930 (medium, CVSS 4.0 6.0)
Apache Pulsar: Improper Authorization of Function, Source and Sink
Package URLs Allows Cross-Tenant Package Download
When registering or updating a function, source or sink from a package
URL, the Functions worker did not check the caller's permission on the
namespace of the package and downloaded it with its own credentials. A
user allowed to register functions in their own tenant could obtain
packages stored in another tenant.
Affected: 2.8.0 before 4.0.14; 4.1.0 through 4.1.3; 4.2.0 before 4.2.5
https://lists.apache.org/thread/dqschrfvb7l0sdhj4sx1qccyywbfp4jg
CVE-2026-105926 (medium, CVSS 4.0 5.3)
Apache Pulsar: Missing Topic Authorization on Binary Protocol GetSchema
and GetOrCreateSchema Commands
The GetSchema and GetOrCreateSchema commands of the binary protocol did
not check topic authorization. An authenticated client could read the
schema of, and register a new schema version on, a topic in another
tenant. Message payloads were not disclosed.
Affected: 2.2.0 before 4.0.14; 4.1.0 through 4.1.3; 4.2.0 before 4.2.5
https://lists.apache.org/thread/45y22fqoqyfpc2hdmoct8cmgslz8ogkh
CVE-2026-105936 (medium, CVSS 4.0 5.3)
Apache Pulsar: Functions connectors list endpoint does not apply the
super-user check of the worker connectors endpoint
The deprecated functions connectors endpoint returned the catalog of
installed Pulsar IO connectors without the super-user check applied by
the worker connectors endpoint, so any authenticated client could read it.
Affected: 2.4.1 before 4.0.14; 4.1.0 before 4.2.5
https://lists.apache.org/thread/dn0cg4l3yolw90f8rjyvv4dl7k340jkz
CVE-2026-105935 (medium, CVSS 4.0 4.9)
Apache Pulsar: Function trigger publishes to the input topic without
checking the caller's produce permission
The Functions worker trigger endpoint did not check that the caller may
produce to the function's input topic, and published the message with
the worker's own credentials. A user allowed to manage functions in a
namespace could publish messages to input topics they cannot produce to,
including topics in other tenants.
Affected: 2.0.0-rc1-incubating before 4.0.14; 4.1.0 before 4.2.5
https://lists.apache.org/thread/nrk7hkyzgo447gm58ry6n8ohl8z5j6nl
CVE-2026-105927 (low, CVSS 4.0 2.3)
Apache Pulsar: Improper authorization of WebSocket consumer dead letter
topic allows writes without PRODUCE permission
The WebSocket service did not check the PRODUCE permission on the topic
named in a consumer's deadLetterTopic parameter, and wrote dead letter
messages with its own identity. A user with CONSUME permission on any
topic could write messages to topics in other tenants.
Affected: 2.3.0 before 4.0.14; 4.1.0 before 4.2.5
https://lists.apache.org/thread/1577zmjsxssb9zkg34sjzcl71om145bd
CVE-2026-105931 (low, CVSS 4.0 2.3)
Apache Pulsar: Missing authorization on transaction admin endpoints
exposes transaction coordinator and transaction statistics of other tenants
Most read endpoints of the transaction admin REST API did not check the
caller's permissions, so any authenticated user could read transaction
coordinator, transaction and transaction buffer information of other
tenants.
Affected: 2.8.0 before 4.0.14; 4.1.0 before 4.2.5
https://lists.apache.org/thread/82g78kf9q7gmf9m8fvsryq78g4chwktz
CVE-2026-105932 (low, CVSS 4.0 2.3)
Apache Pulsar: Missing topic policy authorization on non-persistent
topic entry filter endpoints
The admin REST API endpoints for the topic-level entry filter policy of
non-persistent topics lacked the topic policy authorization check, so a
user with produce or consume permission could read, replace or remove
the policy. Practical impact requires operator-installed entry filters
and allowOverrideEntryFilters=true, neither of which is the default.
Affected: 3.3.0 before 4.0.14; 4.1.0 before 4.2.5
https://lists.apache.org/thread/y30v2pv2gyj3kn4p1xxmgzfv73x6v1mo
CVE-2026-105933 (low, CVSS 4.0 2.3)
Apache Pulsar: Namespace encryption requirement not enforced after a
failure during topic initialization
If a step of topic initialization failed, the broker disabled the
namespace's encryption_required policy for that topic and served it
anyway, so messages published without encryption were accepted.
Affected: 1.22.0-incubating before 4.0.14; 4.1.0 before 4.2.5
https://lists.apache.org/thread/f9xdlh72zf7got2y3vxww5fv4rxvmjbq
CVE-2026-105938 (low, CVSS 4.0 2.3)
Apache Pulsar: Subscription authorization policies not enforced by
namespace-level backlog and unsubscribe operations and by topic expire-all
The namespace-level and bundle-level clear backlog and unsubscribe
operations, and the topic-level expire-all operation, did not apply
subscription authorization policies (the Prefix subscription
authentication mode or subscription permissions). A user with consume
permission could clear, expire or delete subscriptions that the policies
deny to that user.
Affected: 2.8.0 before 4.0.14; 4.1.0 before 4.2.5
https://lists.apache.org/thread/zhc6wjydybdd1msnlcxmmbg8oj0kjmog
Regards,
Lari Hotari
on behalf of the Apache Pulsar PMC
