CVE-2026-42335: MaxKB: SSRF Bypass in MaxKB OSS URL Fetch due to URL Parsing Discrepancy
Vulnerability summary
CVE-2026-42335 is a medium (CVSS 6.3) Server-Side Request Forgery vulnerability in 1panel-dev maxkb. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 14.1% of scored vulnerabilities.
Not severe (CVSS 6.3, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Timeline
- 26-05-2026PublishedVulnerability first disclosed.
- 27-05-2026Last modifiedVulnerability information updated.
Description
MaxKB is an open-source AI assistant for enterprise. Prior to 2.8.1, MaxKB v2.8.0 and prior are vulnerable to a server-side request forgery (SSRF) bypass in the OSS file service URL fetch (chat/api/oss/get_url) endpoint. The vulnerability exists due to inconsistent URL parsing between the urlparse validation function and the requests HTTP client, allowing attackers to access internal network services. This vulnerability is fixed in 2.8.1.
CVSS metrics
2 scores · 2 sources · 1 version- NVDNIST6.3MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS trend
Probability
0.23%
Chance of exploitation in the next 30 days
Percentile
14%
Versus all other CVEs
30-day change
Decrease -0.14 pp
From 0.37% on 04-10-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
1panel-dev1 product
- maxkb< 2.8.1
1 vendor · 1 product
References
1 links- github.com/1Panel-dev/MaxKB/security/advisories/GHSA-r8hf-mwwr-hxgcX Refsource CONFIRM