MaxKB: Broken Access Control in MaxKB OSS URL Fetch API
MaxKB is an open-source AI assistant for enterprise. MaxKB 2.8.0 and prior are vulnerable to a broken access control vulnerability in the OSS file service URL fetch API (chat/api/oss/get_url). The endpoint uses application_id from the URL path without validating ownership, allowing attackers to perform operations under other applications’ policies. This vulnerability is fixed in 2.8.1.
- Published
- May 26, 2026
- Updated
- Jul 23, 2026
- EPSS
- 0.4% · 26th percentile
- CWE
- CWE-862
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Report tools
Action score
21
Monitor
Low priority for now.
- CVSS
- 21 / 40 · 5.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 5.3
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
1Panel-dev MaxKB
- < 2.8.1affected
Same product
1panel-dev: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-77521MaxKB: Prompt-injectable agent can lead to command execution40Plan
- CVE-2026-79916MaxKB AWS Bedrock model credential injection leads to remote code execution36Monitor
- CVE-2026-54149MaxKB MCP tool import validation bypass allows post-authentication remote code execution35Monitor
- CVE-2026-44847MaxKB: Webhook Trigger Authentication Bypass30Monitor
- CVE-2026-77523MaxKB: Cross-workspace model parameter form write29Monitor
- CVE-2026-45413MaxKB: Unsalted MD5 Password Hashing27Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| 1Panel-dev MaxKB | 2.8.1 · description | Vendor (CNA) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-77520118 days apartMaxKB: Homepage ranking leaks application IDs that workflow application-nodes can use to invoke another user's application21Monitor
- CVE-2026-77518118 days apartMaxKB: Known MCP tool IDs expose owner Tool.code and can be referenced by attacker workflows20Monitor
- CVE-2026-77525118 days apartMaxKB: Management chat-record routes trust path application_id but load ChatRecord by global chat_id16Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-862 · Missing AuthorizationCVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/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
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.