Evidence used
- No CISA KEV confirmation is currently recorded.
- Exploitation requires an existing local or physical foothold with privileges.
- EPSS is 0.13% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-82429High confidence
Apache Storm Worker Launcher: Local Privilege Escalation to Root via a Time-of-Check Race in the Worker Launcher
Apache Software Foundation · Apache Storm Worker Launcher
7.8HighCVSS 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:Medium, lowered one band.downgradedsince 14 Sep 2026
Compensating controls
- Restrict local access and enforce least privilege on affected hosts.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Apache Software Foundation Apache Storm Worker Launcher 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 The setuid-root `worker-launcher` binary adjusts ownership and permissions of worker directories by walking the tree with FTS and calling `lchown` and `chmod` on each entry's full pathname while running with an effective uid of 0. Both syscalls re-resolve the path at the time of the call, after FTS has classified the entry, and the trees being walked are owned and writable by the untrusted topology user. A tenant running code on a supervisor node could therefore replace an intermediate directory component with a symbolic link between classification and the privileged operation, redirecting the root-owned `lchown` or `chmod` at an arbitrary file on the host. The operation is repeatable at will, since crashing a worker forces a relaunch and blob updates re-run the walk, so a failed attempt costs the attacker nothing. This crosses the boundary that `supervisor.run.worker.as.user` and container isolation are intended to enforce. It is the same defect class as the Hadoop container-executor issues from which this code derives. Mitigation Upgrade to 3.1.0, where the privileged walk operates on file descriptors it has already stat'd rather than on pathnames re-resolved at call time. Users who cannot upgrade immediately should not run untrusted topology code on supervisors configured with `supervisor.run.worker.as.user`, since the launcher is the boundary being crossed. Note that the launcher must be rebuilt and reinstalled after upgrading; replacing the Java artifacts alone is not sufficient. Credit The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.
What
Description The setuid-root `worker-launcher` binary adjusts ownership and permissions of worker directories by walking the tree with FTS and calling `lchown` and `chmod` on each entry's full pathname while running with an effective uid of 0. Both syscalls re-resolve the path at the time of the call, after FTS has classified the entry, and the trees being walked are owned and writable by the untrusted topology user. A tenant running code on a supervisor node could therefore replace an intermediate directory component with a symbolic link between classification and the privileged operation, redirecting the root-owned `lchown` or `chmod` at an arbitrary file on the host. The operation is repeatable at will, since crashing a worker forces a relaunch and blob updates re-run the walk, so a failed attempt costs the attacker nothing. This crosses the boundary that `supervisor.run.worker.as.user` and container isolation are intended to enforce. It is the same defect class as the Hadoop container-executor issues from which this code derives. Mitigation Upgrade to 3.1.0, where the privileged walk operates on file descriptors it has already stat'd rather than on pathnames re-resolved at call time. Users who cannot upgrade immediately should not run untrusted topology code on supervisors configured with `supervisor.run.worker.as.user`, since the launcher is the boundary being crossed. Note that the launcher must be rebuilt and reinstalled after upgrading; replacing the Java artifacts alone is not sufficient. Credit The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.
Why
The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
How
An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.
What
Description The setuid-root `worker-launcher` binary adjusts ownership and permissions of worker directories by walking the tree with FTS and calling `lchown` and `chmod` on each entry's full pathname while running with an effective uid of 0. Both syscalls re-resolve the path at the time of the call, after FTS has classified the entry, and the trees being walked are owned and writable by the untrusted topology user. A tenant running code on a supervisor node could therefore replace an intermediate directory component with a symbolic link between classification and the privileged operation, redirecting the root-owned `lchown` or `chmod` at an arbitrary file on the host. The operation is repeatable at will, since crashing a worker forces a relaunch and blob updates re-run the walk, so a failed attempt costs the attacker nothing. This crosses the boundary that `supervisor.run.worker.as.user` and container isolation are intended to enforce. It is the same defect class as the Hadoop container-executor issues from which this code derives. Mitigation Upgrade to 3.1.0, where the privileged walk operates on file descriptors it has already stat'd rather than on pathnames re-resolved at call time. Users who cannot upgrade immediately should not run untrusted topology code on supervisors configured with `supervisor.run.worker.as.user`, since the launcher is the boundary being crossed. Note that the launcher must be rebuilt and reinstalled after upgrading; replacing the Java artifacts alone is not sufficient. Credit The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.
Why
The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
How
An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.
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
- local access → Time-of-check Time-of-use (TOCTOU) Race Condition → disrupt the affected service
- Attack surface
- Local
- 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-367 ↗
CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition. The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVLocalAttack vector: The attacker needs local access to the vulnerable system.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.AHighAvailability impact: A successful attack can cause a major loss.- Post-exploitation / living off the land
- The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
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 Worker Launcher: 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. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 14 Sept 2026 · Last source change 14 Sept 2026, 20:00 UTC · CWE-367 · Time-of-check Time-of-use (TOCTOU) Race Condition
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-2026-77528
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-2026-77528 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-77528"}
- SeveritySeverity changed from Unknown to High.CISA ADP ↗
- Before
- Unknown
- After
- High
- CVSS scoreCVSS score changed from not recorded to 7.8 (CVSS 3.1 · CISA ADP · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).CISA ADP ↗
- Before
- not recorded
- After
- 7.8 (CVSS 3.1 · CISA ADP · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
- 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.