CVE-2026-56021: webmin Incorrect Regular Expression
CVSS: 6.9v4.0MediumAnalyzed
Published 18-06-2026Last modified 24-06-2026
Vulnerability summary
CVE-2026-56021 is a medium (CVSS 6.9) Incorrect Regular Expression vulnerability in webmin. EPSS estimates a 0.48% chance of exploitation in the next 30 days, higher than 40.1% of scored vulnerabilities.
CVSS score
6.9/10
010
Medium · v4.0 (CVE.org)EPSS score
0.48%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 18-06-2026PublishedVulnerability first disclosed.
- 24-06-2026Last modifiedVulnerability information updated.
Description
Webmin allows unauthenticated attackers to read the contents of any file ending in .conf within module directories, due to a bypassable regex pattern.
CVSS metrics
4 scores · 2 sources · 2 versionsMedium 6.9Preferred score · CVE.org (CNA)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:NSourcesAll 2 agree
- NVDNIST6.9MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/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
Medium 5.3Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:NSourcesAll 2 agree
- NVDNIST5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS trend
Probability
0.48%
Chance of exploitation in the next 30 days
Percentile
40%
Versus all other CVEs
30-day change
0.00 pp
From 0.48% on 21-09-2026
21-09-202621-10-2026
EPSS score0.48%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-185Incorrect Regular ExpressionThe product specifies a regular expression in a way that causes data to be improperly matched or compared.
- CWE-777Regular Expression without AnchorsThe product uses a regular expression to perform neutralization, but the regular expression is not anchored and may allow malicious or malformed data to slip through.
Affected systems
Webmin1 product
- webminAll versions (No fix recorded) | < 1.290
1 vendor · 1 product