How severe is CVE-2026-35337?

CVE-2026-35337 has a CVSS score of 8.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-35337?

CVE-2026-35337 affects the following packages: org.apache.storm:storm-client (Maven). Ecosystems affected: Maven.

How do I fix CVE-2026-35337?

Update org.apache.storm:storm-client to 2.8.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-35337 is resolved across your whole dependency graph.

How do I detect CVE-2026-35337 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.storm:storm-client, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-35337 if there is no patch (or I can't update yet)?

Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Is CVE-2026-35337 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-35337 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-35337?

CVE-2026-35337 has an EPSS (Exploit Prediction Scoring System) score of 1.0%, placing it in the 64th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-35337?

CVE-2026-35337 is classified as Deserialization of Untrusted Data (CWE-502). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-35337 published, and has it been updated?

CVE-2026-35337 was published on April 13, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

HIGH severity

CVE-2026-35337 — storm-client

HIGH

CVE-2026-35337 is a high-severity (CVSS 8.8) Deserialization of Untrusted Data vulnerability in org.apache.storm:storm-client. A fix is available for org.apache.storm:storm-client — see the affected versions and patch details below.

Apache Storm Client: RCE through Unsafe Deserialization via Kerberos TGT Credential Handling

Also known asGHSA-jf89-3q6q-vcgr

Published

Apr 13, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-35337.

EPSS Exploitation Probability

via FIRST.org ↗

1.0%probability of exploitation in next 30 days

Lower Risk+0.02%

Lower risk than most CVEs64th percentile — riskier than 64% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

☕org.apache.storm:storm-client

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Deserialization of Untrusted Data vulnerability in Apache Storm.

Versions Affected: before 2.8.6.

Description: When processing topology credentials submitted via the Nimbus Thrift API, Storm deserializes the base64-encoded TGT blob using ObjectInputStream.readObject() without any class filtering or validation. An authenticated user with topology submission rights could supply a crafted serialized object in the "TGT" credential field, leading to remote code execution in both the Nimbus and Worker JVMs.

Mitigation: 2.x users should upgrade to 2.8.6.

Users who cannot upgrade immediately should monkey-patch an ObjectInputFilter allow-list to ClientAuthUtils.deserializeKerberosTicket() restricting deserialized classes to javax.security.auth.kerberos.KerberosTicket and its known dependencies. A guide on how to do this is available in the release notes of 2.8.6.

Credit: This issue was discovered by K.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.storm:storm-client`	all versions	2.8.6`org.apache.storm:storm-client:2.8.6`

Affected Products

1 product · 1 configurations

Application

stormapache

≥ 2.0.0 && < 2.8.6

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.storm:storm-client, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.storm:storm-client to 2.8.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-35337 is resolved across your whole dependency graph.
Workarounds
Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Frequently Asked Questions

Deserialization of Untrusted Data vulnerability in Apache Storm. Versions Affected: before 2.8.6. Description: When processing topology credentials submitted via the Nimbus Thrift API, Storm deserializes the base64-encoded TGT blob using ObjectInputStream.readObject() without any class filtering or validation. An authenticated user with topology submission rights could supply a crafted serialized object in the "TGT" credential field, leading to remote code execution in both the Nimbus and Worker JVMs. Mitigation: 2.x users should upgrade to 2.8.6. Users who cannot upgrade immediately sh

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CVSS Score

8.8/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Raw vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWE Classification

CWE-502Deserialization of Untrusted Data

Weaponization

No Nuclei template, Metasploit module or public proof-of-concept found.

Timeline

Disclosed

Apr 13, 2026

Last updated

Oct 28, 2026

Identifiers

CVE-2026-35337

GHSA-jf89-3q6q-vcgr

References

Advisorygithub.com · CVE 2026 35337.json Advisorynvd.nist.gov · CVE 2026 35337 Advisorystorm.apache.org · storm286 released Webopenwall.com Webrepo.maven.apache.org · maven2 Packagegithub.com · storm

Related vulnerabilities

Also affects storm-client

This CVE is high severity — higher than any of the other 1 CVE affecting storm-client (highest there: moderate).

CVE-2026-41081

Same weakness: CWE-502

This CVE is high severity; 6 of 7 other CVEs with CWE-502 are rated as high or higher (top: critical).

CVE-2026-115878CVE-2026-62848CVE-2026-115912CVE-2026-116580CVE-2026-114608CVE-2026-102554GHSA-673q-mjm6-r5xrBrowse all CWE-502

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 28, 2026

CVE-2026-35337 — storm-client

Exploitation Status

No confirmed exploitation observed yet

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2026-35337 in your dependencies?