PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-42335 1Panel-dev CVE debrief

CVE-2026-42335 is a server-side request forgery (SSRF) vulnerability in MaxKB, an open-source AI assistant for enterprise environments. The vulnerability affects versions 2.8.0 and prior, with a fix released in version 2.8.1. The flaw resides in the OSS file service URL fetch endpoint (`chat/api/oss/get_url`), where inconsistent URL parsing between the `urlparse` validation function and the `requests` HTTP client allows attackers to bypass SSRF protections and access internal network services. The CVSS 4.0 vector indicates network attack vector, low attack complexity, low privileges required, and high impact to system confidentiality with low impact to system integrity. The vulnerability is classified under CWE-918 (Server-Side Request Forgery). The issue was disclosed via GitHub Security Advisory GHSA-r8hf-mwwr-hxgc.

Vendor
1Panel-dev
Product
MaxKB
CVSS
MEDIUM 6.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-26
Original CVE updated
2026-07-23
Advisory published
2026-05-26
Advisory updated
2026-07-23

Who should care

Organizations running MaxKB versions prior to 2.8.1 in production environments, particularly those with MaxKB deployed in networks with access to sensitive internal services, cloud metadata endpoints, or infrastructure APIs. Security teams responsible for AI/ML platform security and developers maintaining MaxKB deployments should prioritize this patch.

Technical summary

The vulnerability stems from a parsing differential between Python's `urlparse` module and the `requests` library when handling URLs. Attackers can craft URLs that pass `urlparse` validation but are interpreted differently by `requests`, enabling access to internal IP addresses, localhost, or other restricted destinations. The affected endpoint `/chat/api/oss/get_url` is designed to fetch remote file URLs for OSS (Object Storage Service) operations, making it a high-value target for SSRF exploitation. The CVSS 4.0 scoring reflects significant system confidentiality impact (SC:H) with limited integrity impact (SI:L), consistent with information disclosure capabilities typical of SSRF attacks.

Defensive priority

medium

Recommended defensive actions

  • Upgrade MaxKB to version 2.8.1 or later to remediate the SSRF vulnerability
  • Review and restrict network access for MaxKB deployments to limit exposure of internal services
  • Implement additional SSRF protections such as URL canonicalization and allowlist-based validation independent of the HTTP client
  • Monitor application logs for suspicious URL fetch requests to the `/chat/api/oss/get_url` endpoint
  • Conduct security review of other URL-fetching functionality in MaxKB for similar parsing inconsistencies

Evidence notes

Vulnerability description sourced from NVD record and GitHub Security Advisory. CVSS 4.0 vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N. CWE-918 classification confirmed via weakness data. Fix version 2.8.1 explicitly stated in advisory.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-42335 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-42335

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-42335 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-42335

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.