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Full vulnerability report · 2026
CVE-2026-105945High confidence

Apache Pulsar: Improper Validation of Package Name Components Allows Cross-Tenant Package Access in Filesystem Package Storage

Apache Software Foundation · Apache Pulsar

7.7HighCVSS 4.0
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:High, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • EPSS is 0.49% for the current model date.

Compensating controls

  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Apache Software Foundation Apache Pulsar and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 30 daysRemediation target: Within 180 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-107480

No EUVD known-exploited evidence

The Pulsar Packages Management Service can be configured to store packages on the local filesystem of the broker by using the filesystem storage provider. Package names consist of a type, tenant, namespace, name and version. Authorization of package operations is based only on the tenant and namespace, while the storage location of a package is derived from all of these components. The version component of a package name was not validated, so it could contain URL-encoded path separators and parent directory references. The filesystem storage provider resolved such a version to a location belonging to a package in a different tenant or namespace. Because that location is inside the configured storage directory, the containment check that the filesystem storage provider performs in recent releases did not prevent the access. An authenticated user who has the packages permission on any namespace could use this to download, overwrite or delete packages stored in other tenants or namespaces for which the user has no permission. Packages overwritten or deleted in this way may be used by Pulsar Functions, Sources or Sinks, so the issue can affect the integrity and availability of these components. If authentication is disabled, the operations are available to any client that can reach the broker's admin REST API. This issue only affects deployments in which package management is enabled with the broker setting enablePackagesManagement and the filesystem storage provider (FileSystemPackagesStorageProvider) is configured with the setting packagesManagementStorageProvider. Package management is disabled by default, and the default storage provider, which stores packages in Apache BookKeeper, is not affected. This issue affects Apache Pulsar versions from 2.10.0 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/.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
7.7 · CVSS 4.0
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified
01

What, why and how

The Pulsar Packages Management Service can be configured to store packages on the local filesystem of the broker by using the filesystem storage provider. Package names consist of a type, tenant, namespace, name and version. Authorization of package operations is based only on the tenant and namespace, while the storage location of a package is derived from all of these components. The version component of a package name was not validated, so it could contain URL-encoded path separators and parent directory references. The filesystem storage provider resolved such a version to a location belonging to a package in a different tenant or namespace. Because that location is inside the configured storage directory, the containment check that the filesystem storage provider performs in recent releases did not prevent the access. An authenticated user who has the packages permission on any namespace could use this to download, overwrite or delete packages stored in other tenants or namespaces for which the user has no permission. Packages overwritten or deleted in this way may be used by Pulsar Functions, Sources or Sinks, so the issue can affect the integrity and availability of these components. If authentication is disabled, the operations are available to any client that can reach the broker's admin REST API. This issue only affects deployments in which package management is enabled with the broker setting enablePackagesManagement and the filesystem storage provider (FileSystemPackagesStorageProvider) is configured with the setting packagesManagementStorageProvider. Package management is disabled by default, and the default storage provider, which stores packages in Apache BookKeeper, is not affected. This issue affects Apache Pulsar versions from 2.10.0 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/.

What

The Pulsar Packages Management Service can be configured to store packages on the local filesystem of the broker by using the filesystem storage provider. Package names consist of a type, tenant, namespace, name and version. Authorization of package operations is based only on the tenant and namespace, while the storage location of a package is derived from all of these components. The version component of a package name was not validated, so it could contain URL-encoded path separators and parent directory references. The filesystem storage provider resolved such a version to a location belonging to a package in a different tenant or namespace. Because that location is inside the configured storage directory, the containment check that the filesystem storage provider performs in recent releases did not prevent the access. An authenticated user who has the packages permission on any namespace could use this to download, overwrite or delete packages stored in other tenants or namespaces for which the user has no permission. Packages overwritten or deleted in this way may be used by Pulsar Functions, Sources or Sinks, so the issue can affect the integrity and availability of these components. If authentication is disabled, the operations are available to any client that can reach the broker's admin REST API. This issue only affects deployments in which package management is enabled with the broker setting enablePackagesManagement and the filesystem storage provider (FileSystemPackagesStorageProvider) is configured with the setting packagesManagementStorageProvider. Package management is disabled by default, and the default storage provider, which stores packages in Apache BookKeeper, is not affected. This issue affects Apache Pulsar versions from 2.10.0 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/.

Why

Attacker-controlled path data is not constrained to the intended directory before the application accesses a file.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

The Pulsar Packages Management Service can be configured to store packages on the local filesystem of the broker by using the filesystem storage provider. Package names consist of a type, tenant, namespace, name and version. Authorization of package operations is based only on the tenant and namespace, while the storage location of a package is derived from all of these components. The version component of a package name was not validated, so it could contain URL-encoded path separators and parent directory references. The filesystem storage provider resolved such a version to a location belonging to a package in a different tenant or namespace. Because that location is inside the configured storage directory, the containment check that the filesystem storage provider performs in recent releases did not prevent the access. An authenticated user who has the packages permission on any namespace could use this to download, overwrite or delete packages stored in other tenants or namespaces for which the user has no permission. Packages overwritten or deleted in this way may be used by Pulsar Functions, Sources or Sinks, so the issue can affect the integrity and availability of these components. If authentication is disabled, the operations are available to any client that can reach the broker's admin REST API. This issue only affects deployments in which package management is enabled with the broker setting enablePackagesManagement and the filesystem storage provider (FileSystemPackagesStorageProvider) is configured with the setting packagesManagementStorageProvider. Package management is disabled by default, and the default storage provider, which stores packages in Apache BookKeeper, is not affected. This issue affects Apache Pulsar versions from 2.10.0 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/.

Why

Attacker-controlled path data is not constrained to the intended directory before the application accesses a file.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-22 ↗

CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'). The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:L/SA:L

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATPresentAttack requirements: A particular deployment or execution condition must be present.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.VIHighVulnerable-system integrity: A successful attack can cause a major loss.VAHighVulnerable-system availability: A successful attack can cause a major loss.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SILowSubsequent-system integrity: A successful attack can cause a limited loss.SALowSubsequent-system availability: A successful attack can cause a limited loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkCWE-22
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-107480Official EUVD mapping

The Pulsar Packages Management Service can be configured to store packages on the local filesystem of the broker by using the filesystem storage provider. Package names consist of a type, tenant, namespace, name and version. Authorization of package operations is based only on the tenant and namespace, while the storage location of a package is derived from all of these components. The version component of a package name was not validated, so it could contain URL-encoded path separators and parent directory references. The filesystem storage provider resolved such a version to a location belonging to a package in a different tenant or namespace. Because that location is inside the configured storage directory, the containment check that the filesystem storage provider performs in recent releases did not prevent the access. An authenticated user who has the packages permission on any namespace could use this to download, overwrite or delete packages stored in other tenants or namespaces for which the user has no permission. Packages overwritten or deleted in this way may be used by Pulsar Functions, Sources or Sinks, so the issue can affect the integrity and availability of these components. If authentication is disabled, the operations are available to any client that can reach the broker's admin REST API. This issue only affects deployments in which package management is enabled with the broker setting enablePackagesManagement and the filesystem storage provider (FileSystemPackagesStorageProvider) is configured with the setting packagesManagementStorageProvider. Package management is disabled by default, and the default storage provider, which stores packages in Apache BookKeeper, is not affected. This issue affects Apache Pulsar versions from 2.10.0 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/.

Official EUVD record ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix not verified
Affected
Apache Pulsar: 2.10.0 < 4.0.14, 4.1.0 < 4.2.5
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 21 Oct 2026 · Last source change 21 Oct 2026, 18:18 UTC · CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-10-22
European sourceENISA EUVD · EUVD-2026-107480
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD awaiting enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. ENISA EUVD mappingEUVD-2026-107480 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2026-107480"}
    ENISA EUVD ↗
  2. Vendor guidanceAuthoritative vendor guidance changed: removed vendor advisory: lists.apache.org/o5jt8zrg1qxqdrqlb06jjmj4lzydfm2k; removed vendor advisory: pulsar.apache.org/CVE-2026-105945.
    Before
    vendor advisory: lists.apache.org/o5jt8zrg1qxqdrqlb06jjmj4lzydfm2k · vendor advisory: pulsar.apache.org/CVE-2026-105945
    After
    no authoritative guidance recorded
    CNA ↗
  3. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2026-107480↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-105945 · cve.blacktree.nl