CVE-2026-42455Public exploitNetwork attack vector

Stored XSS via unsanitized same-origin archive uploads

Published May 8, 2026 · Updated May 8, 2026

Stored XSS in Linkwarden 2.14.0 and earlier allows remote attackers to execute JavaScript in an authenticated user's session via HTML archive uploads. The archive API stores uploaded text/html content without stripping scripts, then returns it from the application origin as text/html without CSP or download-only headers. Execution occurs when the stored archive is retrieved, exposing the active session token and permitting reads of links, collections, and user data available to that session.

CVSS severity8.8
High
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Linkwarden 2.14.0 and earlier allows remote attackers to execute JavaScript in an authenticated user's session via HTML archive uploads. The archive API stores uploaded text/html content without stripping scripts, then returns it from the application origin as text/html without CSP or download-only headers. Execution occurs when the stored archive is retrieved, exposing the active session token and permitting reads of links, collections, and user data available to that session.

The record

CVE
CVE-2026-42455
Published
May 8, 2026
Updated
May 8, 2026
Vendor
Linkwarden
Product
Linkwarden
Classifications
CWE-79, T1539
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 8, 2026CVE publishedPublication date reported by the CVE source.
  2. May 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=<= 2.14.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Linkwarden · Linkwardenversion=<= 2.14.0

Published CVSS scores

8.8GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1539Steal Web Session Cookie

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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