How severe is CVE-2026-5423?

No CVSS score has been assigned to CVE-2026-5423 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-5423?

Affected package information for CVE-2026-5423 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2026-5423?

Upgrade the affected component to the fixed release for CVE-2026-5423, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.

How do I detect CVE-2026-5423 in my code and dependencies?

Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

How do I mitigate CVE-2026-5423 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2026-5423 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-5423 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-2026-5423?

CVE-2026-5423 has an EPSS (Exploit Prediction Scoring System) score of 0.6%, placing it in the 48th 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-2026-5423?

CVE-2026-5423 is classified as CWE-302 (CWE-302). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Is there exploit tooling available for CVE-2026-5423?

A Metasploit module references CVE-2026-5423, which lowers the barrier to weaponization. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2026-5423 published, and has it been updated?

CVE-2026-5423 was published on August 6, 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.

CVE-2026-5423: graphql

Exploitation Status

No confirmed exploitation observed yet

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-2026-5423.

EPSS Exploitation Probability

via FIRST.org ↗

0.6%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs48th percentile — riskier than 48% of all scored CVEsHighest risk

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

Description

@neo4j/graphql library versions prior to 7.5.6 fail to verify the authenticity of a client-supplied, pre-decoded JWT object passed through GraphQL subscription connectionParams. As a result, any unauthenticated remote client that can open a GraphQL-over-WebSocket connection can forge arbitrary JWT claims (e.g. sub, roles) in connectionParams.jwt and have them accepted as authenticated identity for the purposes of @authentication and @subscriptionsAuthorization directive evaluation. This allows a fully unauthenticated attacker to receive subscription events that should be restricted to specific authenticated roles/users. Upgrade the library to versions 7.5.6+ or 5.12.14+. v6 is end-of-life and will not receive a fix.

Detection & mitigation playbook

Vulnerability

Detect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Fix
Upgrade the affected component to the fixed release for CVE-2026-5423, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

@neo4j/graphql library versions prior to 7.5.6 fail to verify the authenticity of a client-supplied, pre-decoded JWT object passed through GraphQL subscription connectionParams. As a result, any unauthenticated remote client that can open a GraphQL-over-WebSocket connection can forge arbitrary JWT claims (e.g. sub, roles) in connectionParams.jwt and have them accepted as authenticated identity for the purposes of @authentication and @subscriptionsAuthorization directive evaluation. This allows a fully unauthenticated attacker to receive subscription events that should be restricted to specific

O3 Security · Impact-Aware SCA

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CVE-2026-5423 — graphql