The Apache Pulsar broker exposes a transaction administration REST API under /admin/v3/transactions. When authentication and authorization are enabled, most of the read endpoints of this API verify only that the request is authenticated and that the broker serves the requested topic or transaction coordinator. They do not check whether the caller is permitted to access the tenant, namespace or topic whose data is returned. The endpoints that modify state, which abort a transaction or scale the transaction coordinators, correctly require super-user access and are not affected.
As a result, any authenticated user, including one that has been granted no permissions, can read transaction coordinator and transaction information belonging to other tenants. This includes the list of transaction coordinators with the broker service URLs that serve them, transaction coordinator statistics and internal statistics, transaction metadata including the names of the topics and subscriptions a transaction involves and the principal that opened it, the list of long-running transactions on a transaction coordinator, transaction buffer and pending acknowledgement statistics and internal statistics for any topic and subscription, and whether a given message position of a subscription is currently held in a pending transactional acknowledgement.
The disclosure of transaction metadata and statistics can only occur when transaction support is enabled in the broker (transactionCoordinatorEnabled, which is disabled by default). When transaction support is disabled, these endpoints return no transaction data; the only residual effect is that one endpoint's error response can reveal whether a named topic exists in another tenant.
The impact is limited to disclosure of transaction-related metadata and statistics across tenant boundaries. The issue does not allow reading message contents, modifying or aborting transactions, or changing any configuration.
This issue affects Apache Pulsar versions from 2.8.0 before 4.0.14 and from 4.1.0 before 4.2.5.
- 4.0.x version users should upgrade to at least 4.0.14.
- 4.1.x and 4.2.x version users should upgrade to at least 4.2.5.
Users operating versions prior to those listed above should upgrade to the aforementioned patched versions or newer versions.
The currently supported Apache Pulsar release lines are 4.0.x and 5.0.x. The supported versions schedule is available at https://pulsar.apache.org/contribute/release-policy/.
Users who cannot upgrade immediately and do not use Pulsar transactions should keep transaction support disabled. Where transactions are required, restricting network access to the broker's admin HTTP endpoints to trusted administrative clients reduces the exposure.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (2.3): severity, escalated by confirmed exploitation. This CVE's 2.3 is its impact severity (EG Severity), not escalated.
- EG Severity
- 2.3 LOWCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
- EG Likelihood
- 0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
The CVE record names the fixed release. Apply it within your standard update timelines.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact partial (CVSS v4.0 confidentiality and integrity impact neither High). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact partial (CVSS v4.0 confidentiality and integrity impact neither High). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it