CVE-2026-105938

LOWPre-NVD 2.32.3
EchelonGraph scoreLOW confidence

This low-severity CVE scores 2.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: a secondary CVSS source
2.3EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 2.3Exploit: None knownExposed services: Not assessed

The CVE record names the fixed release — apply it.

Apache Pulsar namespaces can restrict which roles may use a subscription, either with the Prefix subscription authentication mode, which requires a subscription name to start with the role name, or by granting permission on a subscription to specific roles. Topic-level subscription operations, such as consuming, skipping messages, resetting a cursor or deleting a subscription, apply these subscription policies. Several admin REST API operations that act on subscriptions did not apply them:

  • the namespace-level and bundle-level clear backlog operations, both for a named subscription and for all subscriptions;
  • the namespace-level and bundle-level unsubscribe operations;
  • the topic-level operation that expires messages for all subscriptions of a topic.

With the default authorization provider, the namespace-level operations require only consume permission granted on the namespace, and the expire-all operation requires only consume permission on the topic. As a result, when authentication and authorization are enabled and a namespace uses the Prefix subscription authentication mode or subscription permissions, an authenticated user with such consume permission can clear the backlog of, expire messages of, or delete a subscription that the policies would deny to that user. Tenant admin or superuser access is not required. The clear backlog operations can also be applied to the cursors used for geo-replication, so that messages not yet replicated to a remote cluster are skipped. Deployments that do not configure the Prefix subscription authentication mode or subscription permissions (the defaults) are not affected by this bypass, because consume permission on the namespace or topic already allows these operations there. This impact analysis assumes that Pulsar has been configured with the default authorization provider. For custom authorization providers, the impact could be different.

The impact is on the integrity of subscription state. Clearing or expiring the backlog moves the subscription's cursor forward, so unacknowledged messages are no longer delivered to the subscription's consumers. The unsubscribe operation deletes a subscription that has no connected consumers. Skipped messages can be permanently deleted once no other subscription or the namespace's retention policy keeps them. The issue does not allow reading message contents, changing permissions or policies, or accessing other namespaces, and it does not affect the availability of the broker.

In fixed versions, the namespace-level and bundle-level operations for a named subscription apply the subscription policies to that subscription, and the operations for all subscriptions, when requested by a user who is not a tenant admin or superuser, only act on the subscriptions that the user may access. Clearing the backlog of geo-replication cursors requires tenant admin or superuser access. Topic-level subscription operations apply the subscription policies for all types of authentication data, including that of the anonymous user role.

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.

All brokers in a cluster must be upgraded before relying on the namespace-level restrictions, because brokers that have not been upgraded do not apply them when they receive the internal per-bundle requests.

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 can reduce exposure by restricting network access to the broker's admin REST API to trusted administrative clients.

CVSS v3
2.3
EG Score
2.3LOWlow confidence
EG Risk
10
EG Risk 10/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity23% × 45%
Impact severity (EG Severity): CVSS 2.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0% × 40%
No KEV listing, EG-KEV tier or EPSS when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
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.
Action: The CVE record names the fixed release. Apply it within your standard update timelines.
EPSS PROB
—
EPSS %ILE
—
KEV
Not listed

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
Unknown (no EPSS on record)Unknown, not low: FIRST has published no EPSS probability for this CVE.
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

Published

October 21, 2026

Last Modified

October 21, 2026

References (2)

Vendor Advisories for CVE-2026-105938(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 3× in last 7d / 3× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

  1. 2026-10-21 19:28 UTCEG score recompute
  2. 2026-10-21 18:31 UTCEG score recomputeFirst assessed: 2.3 LOW
  3. 2026-10-21 18:30 UTCMITRE cvelistV5first tracked

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Frequently asked(4)

What is CVE-2026-105938?
CVE-2026-105938 is a low-severity vulnerability; its CVE record was published on October 21, 2026. Apache Pulsar namespaces can restrict which roles may use a subscription, either with the Prefix subscription authentication mode, which requires a subscription name to start with the role name, or by granting permission on a subscription to specific roles. Topic-level subscription operations, such…
When was the CVE record for CVE-2026-105938 published?
The CVE record for CVE-2026-105938 was published on October 21, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 21, 2026; the record at its source may have been updated since.
What is the CVSS score of CVE-2026-105938?
CVE-2026-105938 has a CVSS base score of 2.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-105938?
The CVE record for CVE-2026-105938 names the fix: "- 4.0.x version users should upgrade to at least 4.0.14." The vendor advisories EchelonGraph has for CVE-2026-105938 are linked in the Vendor Advisories panel on this page.

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