Webmin HTTP header authentication bypass
Priority MEDIUM 42CWE-290Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-290.
Summary
The Webmin HTTP server (miniserv.pl) allows unauthenticated attackers to impersonate any user with a configured SSL client certificate by sending a forged HTTP header. A remote attacker can spoof certificate DNs and authenticate as any user. Fixed in 2.202.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00495 42nd percentileScored 2026-11-07
Fix Fixed Webmin (Webmin): 2.202
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA Webmin (Webmin) Fixed in 2.202
Timeline
- 2026-10-02 Threatist record created from CVE-2026-56020
- 2026-10-03 Alias added: GHSA-23xj-gfh3-wf2h
More Webmin vulnerabilities
- TI-2019-11278 An issue was discovered in Webmin <=1.920. KEVCVSS 3.1CRITICAL 9.8
- TI-2022-16770 software/apt-lib.pl in Webmin before 1.997 lacks HTML escaping for a UI command. CVSS 3.1CRITICAL 9.8
- TI-2022-00731 Improper Access Control to Remote Code Execution in webmin/webmin CVSS 3.1HIGH 8.8
- TI-2019-09619 In Webmin through 1.910, any user authorized to the "Package Updates" module can execute… CVSS 3.0HIGH 8.8
- TI-2015-01866 Code injection in Usermin CVSS 3.1CRITICAL 9.9
- TI-2022-15852 Usermin through 1.850 allows a remote authenticated user to execute OS commands via… CVSS 3.1HIGH 8.8
Sources
- CVE-2026-56020 · CVE Program
- CVE-2026-56020 · NVD
- FIRST EPSS
- GHSA-23xj-gfh3-wf2h · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences