Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.21% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-82438High confidence
Apache Storm Webapp: Authenticated API Responses Exposed to Arbitrary Web Origins
Apache Software Foundation · Apache Storm Webapp
8.1HighCVSS 3.1
Within 7 days
Fix not verifiedHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:High, unchanged from published severity.unchanged
Compensating controls
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Apache Software Foundation Apache Storm Webapp and falls inside the recorded affected range.
- Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Fix not verified01
What, why and how
Description Three separate mechanisms allowed a web page on an unrelated origin to read responses that Storm's HTTP components served to an authenticated user. The Logviewer reflected the request's `Origin` header back in `Access-Control-Allow-Origin` while also sending `Access-Control-Allow-Credentials: true`. The published security model documents a permissive `Access-Control-Allow-Origin: *` posture as accepted, which is safe precisely because browsers refuse to honour `*` together with credentials; reflecting the concrete origin removes that protection. The shared CORS filter used by the UI, the Logviewer and DRPC was configured with a response header name where an initialisation parameter name was expected. The container ignored the setting and applied its own defaults, which allow credentials. Finally, the UI and Logviewer wrapped API responses in a caller-supplied JSONP callback for every GET request. A script element on any origin can load such a response, which bypasses the same-origin policy entirely rather than negotiating it, and there was no way to turn the behaviour off. In each case the effect is that a page visited by an authenticated operator can read cluster, topology and log data on their behalf. Mitigation Upgrade to 3.1.0, where the Logviewer no longer reflects the request origin in a credentialed response, the CORS filter is configured explicitly, and JSONP wrapping is governed by `ui.enable.jsonp`, which defaults to false. Note that disabling JSONP is a behaviour change for tooling that passes a `callback` query parameter; such tooling should be moved to ordinary JSON requests. Users who cannot upgrade immediately should place the UI, Logviewer and DRPC HTTP endpoints behind a reverse proxy that strips `Access-Control-Allow-Origin` and `Access-Control-Allow-Credentials` from responses and rejects requests carrying a `callback` parameter. Credit The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.
What
Description Three separate mechanisms allowed a web page on an unrelated origin to read responses that Storm's HTTP components served to an authenticated user. The Logviewer reflected the request's `Origin` header back in `Access-Control-Allow-Origin` while also sending `Access-Control-Allow-Credentials: true`. The published security model documents a permissive `Access-Control-Allow-Origin: *` posture as accepted, which is safe precisely because browsers refuse to honour `*` together with credentials; reflecting the concrete origin removes that protection. The shared CORS filter used by the UI, the Logviewer and DRPC was configured with a response header name where an initialisation parameter name was expected. The container ignored the setting and applied its own defaults, which allow credentials. Finally, the UI and Logviewer wrapped API responses in a caller-supplied JSONP callback for every GET request. A script element on any origin can load such a response, which bypasses the same-origin policy entirely rather than negotiating it, and there was no way to turn the behaviour off. In each case the effect is that a page visited by an authenticated operator can read cluster, topology and log data on their behalf. Mitigation Upgrade to 3.1.0, where the Logviewer no longer reflects the request origin in a credentialed response, the CORS filter is configured explicitly, and JSONP wrapping is governed by `ui.enable.jsonp`, which defaults to false. Note that disabling JSONP is a behaviour change for tooling that passes a `callback` query parameter; such tooling should be moved to ordinary JSON requests. Users who cannot upgrade immediately should place the UI, Logviewer and DRPC HTTP endpoints behind a reverse proxy that strips `Access-Control-Allow-Origin` and `Access-Control-Allow-Credentials` from responses and rejects requests carrying a `callback` parameter. Credit The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.
Why
The product does not properly verify that the source of data or communication is valid.
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
Description Three separate mechanisms allowed a web page on an unrelated origin to read responses that Storm's HTTP components served to an authenticated user. The Logviewer reflected the request's `Origin` header back in `Access-Control-Allow-Origin` while also sending `Access-Control-Allow-Credentials: true`. The published security model documents a permissive `Access-Control-Allow-Origin: *` posture as accepted, which is safe precisely because browsers refuse to honour `*` together with credentials; reflecting the concrete origin removes that protection. The shared CORS filter used by the UI, the Logviewer and DRPC was configured with a response header name where an initialisation parameter name was expected. The container ignored the setting and applied its own defaults, which allow credentials. Finally, the UI and Logviewer wrapped API responses in a caller-supplied JSONP callback for every GET request. A script element on any origin can load such a response, which bypasses the same-origin policy entirely rather than negotiating it, and there was no way to turn the behaviour off. In each case the effect is that a page visited by an authenticated operator can read cluster, topology and log data on their behalf. Mitigation Upgrade to 3.1.0, where the Logviewer no longer reflects the request origin in a credentialed response, the CORS filter is configured explicitly, and JSONP wrapping is governed by `ui.enable.jsonp`, which defaults to false. Note that disabling JSONP is a behaviour change for tooling that passes a `callback` query parameter; such tooling should be moved to ordinary JSON requests. Users who cannot upgrade immediately should place the UI, Logviewer and DRPC HTTP endpoints behind a reverse proxy that strips `Access-Control-Allow-Origin` and `Access-Control-Allow-Credentials` from responses and rejects requests carrying a `callback` parameter. Credit The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.
Why
The product does not properly verify that the source of data or communication is valid.
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 No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 → Origin Validation Error → 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
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-346 ↗
CWE-346: Origin Validation Error. The product does not properly verify that the source of data or communication is valid.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:NCommon Vulnerability Scoring System 3.1: 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.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.ANoneAvailability impact: No direct loss is represented by this metric.- Post-exploitation / living off the land
- Stolen credentials, tokens and legitimate administration functions may provide continued access without deploying a large custom toolset.
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 Storm Webapp: 3.0.0 < 3.1.0
- 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 14 Sept 2026 · Last source change 14 Sept 2026, 19:52 UTC · CWE-346 · Origin Validation Error
CVE recordCVE.org · 5.2
CVSS sourceCISA ADP
EPSS source FIRST · tracked since 2026-09-15
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-77514
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD not scheduled
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- ENISA EUVD mappingEUVD-2026-77514 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-77514"}
- SeveritySeverity changed from Unknown to High.CISA ADP ↗
- Before
- Unknown
- After
- High
- CVSS scoreCVSS score changed from not recorded to 8.1 (CVSS 3.1 · CISA ADP · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N).CISA ADP ↗
- Before
- not recorded
- After
- 8.1 (CVSS 3.1 · CISA ADP · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N)
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
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.