Cross-site Scripting (XSS)Weakness · CWE-79

CVE-2026-49102

MEDIUM · 6.1 CVSS v3.1 Published 2026-05-27
Patch available
A vendor patch is available. No clean upgrade release — apply the published patch.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Webmin before 2.640 allows mailboxes/detach.cgi XSS via an SVG document attachment that is viewed in the mailboxes component, because image/svg+xml is used instead of a safe type (e.g., text/plain).

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-79

Untrusted input is placed into a web page without being neutralised, so an attacker's markup or script executes in another user's browser. That can hijack sessions, capture keystrokes, or silently perform actions as the victim. Fixing it properly means context-aware output encoding everywhere data meets HTML, backed by a content-security policy as a second line of defence.

General guidance for the cross-site scripting (xss) class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Patch available Apply the vendor patch
Vendor patch github.com →
Recommended fix Moderate confidence

Webmin 2.640 or later

  1. 1. Identify current Webmin version by checking the Webmin dashboard or running `webmin --version`
  2. 2. Download Webmin version 2.640 or later from the official Webmin repository or website
  3. 3. Backup the current Webmin configuration and data directory before upgrading
  4. 4. Install the upgrade following standard Webmin upgrade procedures
  5. 5. Verify the upgrade was successful by checking the new version number
  6. 6. Test the mailboxes component to confirm SVG attachments are now handled with a safe content type (e.g., text/plain)
Caveat Minor version upgrade; standard Webmin upgrade procedures apply; review release notes for any configuration changes

Generated from the published advisory — verify against the referenced sources before acting.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-49102 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data