How severe is CVE-2026-42336?

CVE-2026-42336 has a CVSS 4.0 base score of 5.1, rated medium severity.

Is CVE-2026-42336 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-42336?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-42336 have an EU (EUVD) identifier?

Yes. CVE-2026-42336 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31989.

When was CVE-2026-42336 published?

CVE-2026-42336 was published on 2026-05-26 and last updated on 2026-06-17.

CVE-2026-42336

CVE-2026-42336 is a medium-severity vulnerability with a CVSS 4.0 base score of 5.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-367.

Key facts

Severity: Medium (CVSS 4.0 base score 5.1)
EPSS exploit prediction: 0% (8th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-31989
Weakness: CWE-367
Published: 2026-05-26
Last modified: 2026-06-17

Description

MaxKB is an open-source AI assistant for enterprise. MaxKB 2.8.0 and prior are vulnerable to a server-side request forgery (SSRF) bypass in the OSS file service URL fetch functionality due to inconsistent DNS resolution between validation and actual request execution, allowing attackers to access internal network services. This vulnerability is fixed in 2.8.1.

Frequently asked questions

What is CVE-2026-42336?: MaxKB is an open-source AI assistant for enterprise. MaxKB 2.8.0 and prior are vulnerable to a server-side request forgery (SSRF) bypass in the OSS file service URL fetch functionality due to inconsistent DNS resolution between validation and actual request execution, allowing attackers to access internal network services. This vulnerability is fixed in 2.8.1.
How severe is CVE-2026-42336?: CVE-2026-42336 has a CVSS 4.0 base score of 5.1, rated medium severity.
Is CVE-2026-42336 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-42336?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-42336 have an EU (EUVD) identifier?: Yes. CVE-2026-42336 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31989.
When was CVE-2026-42336 published?: CVE-2026-42336 was published on 2026-05-26 and last updated on 2026-06-17.

References

https://github.com/1Panel-dev/MaxKB/security/advisories/GHSA-6m4p-9wwc-4q5q

Other CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition) vulnerabilities

CVE-2026-25641 — Critical (CVSS 10.0): SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, there is a sandbox escape vulnerability due to a…
CVE-2025-64180 — Critical (CVSS 10.0): Manager-io/Manager is accounting software. In Manager Desktop and Server versions 25.11.1.3085 and below, a critical…
CVE-2025-34027 — Critical (CVSS 10.0): The Versa Concerto SD-WAN orchestration platform is vulnerable to an authentication bypass in the Traefik reverse proxy…
CVE-2026-25052 — Critical (CVSS 9.9): n8n is an open source workflow automation platform. Prior to versions 1.123.18 and 2.5.0, a vulnerability in the file…
CVE-2025-13032 — Critical (CVSS 9.9): Double fetch in sandbox kernel driver in Avast/AVG Antivirus <25.3 on windows allows local attacker to escalate…
CVE-2026-53838 — Critical (CVSS 9.8): OpenClaw before 2026.5.27 contains a state mutation vulnerability in node pairing reconnection that allows paired nodes…

Browse all CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition) vulnerabilities →