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

CVE-2026-61875

HIGH · 8.8 CVSS v3.1 Published 2026-07-12
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
91/100
Remediation priority · Urgent
No privileges 6 weeks old

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
luci-app-upnp contains a stored cross-site scripting vulnerability that allows unauthenticated LAN clients to inject JavaScript via UPnP IGD AddPortMapping SOAP requests. Attackers can send malicious HTML in the NewPortMappingDescription field, which miniupnpd stores and luci-app-upnp renders without output encoding, executing the payload when administrators view the UPnP or Status pages.

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 · high confidence

A stored XSS vulnerability in luci-app-upnp allows unauthenticated LAN clients to inject malicious JavaScript via the NewPortMappingDescription field in UPnP IGD AddPortMapping SOAP requests. The payload is stored by miniupnpd and rendered without output encoding when administrators access UPnP or Status pages, enabling cookie theft or administrative action hijacking.

MitigationApply output encoding to the NewPortMappingDescription field before rendering in luci-app-upnp administrative pages; alternatively, disable UPnP if not required in the network environment.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

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
Adjacent
Complexity
Low
Privileges
None
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify luci-app-upnp is installed
    On the OpenWrt device, run 'opkg list-installed | grep luci-app-upnp' or check /usr/lib/lua/luci/controller/upnp.lua exists
    Affected if The package is not installed or the lua controller file is missing (not affected)
  2. Confirm miniupnpd service is enabled and running
    Run '/etc/init.d/miniupnpd status' or check 'ps | grep miniupnpd' to see if the UPnP daemon is active
    Affected if miniupnpd is not running (not affected - the persistence vector requires the daemon to store mappings)
  3. Check UPnP port mappings for suspicious descriptions
    Run 'upnpc -l' or inspect /var/miniupnpd.sqlite (or equivalent database) for port mappings - specifically examine the Description field of each mapping
    Affected if Any port mapping contains HTML/script tags in the description field (e.g., <script>, javascript:, onload=) indicating exploitation
  4. Verify luci web interface is accessible
    Attempt to access the luci web interface at the router's IP address on ports 80 or 443
    Affected if luci is accessible to attackers (required for the XSS to execute when admins view the UPnP status page)
  5. Inspect luci UPnP view for unencoded output
    View the UPnP status page in luci (System > Startup > UPnP or Status > UPnP) - check page source for raw HTML from description fields
    Affected if The description field content appears as raw HTML in the page without escaping (vulnerability is present)

User is affected if luci-app-upnp is installed, miniupnpd is enabled and accessible to LAN clients, and the luci web interface renders UPnP port mapping descriptions without HTML escaping.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply output encoding to the NewPortMappingDescription field before rendering in luci-app-upnp administrative pages; alternatively, disable UPnP if not required in the network environment.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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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-2026-61875 in production — separate from our analysis above.

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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
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  • Version or environment caveats, and links to real fixes
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