CVE-2026-59814Public exploitNetwork attack vectorHinoki check available

Stored XSS via inline-served empty-title SVG attachment

Published Sep 21, 2026 · Updated Sep 21, 2026

Stored XSS in Joplin Server before 3.7.7 allows remote authenticated users to run script in a public-share viewer's browser. The GET /shares/:id?resource_id= route copies attacker-controlled MIME metadata into Content-Type and omits Content-Disposition for an empty title, causing an SVG attachment to render inline. A low-privileged account must publish the attachment and a victim must open the share; on the default shared origin, the script can read data and act through the victim's authenticated session.

CVSS severity7.6
High
EPSS probability0.35%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Stored XSS in Joplin Server before 3.7.7 allows remote authenticated users to run script in a public-share viewer's browser. The GET /shares/:id?resource_id= route copies attacker-controlled MIME metadata into Content-Type and omits Content-Disposition for an empty title, causing an SVG attachment to render inline. A low-privileged account must publish the attachment and a victim must open the share; on the default shared origin, the script can read data and act through the victim's authenticated session.

The record

CVE
CVE-2026-59814
Published
Sep 21, 2026
Updated
Sep 21, 2026
Vendor
Joplin Project
Product
Joplin
Classifications
CWE-79, T1189
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 21, 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=< 3.7.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Joplin Project · Joplinversion=< 3.7.7

Published CVSS scores

7.6Joplin ProjectCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A: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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

Public exploit references

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

Technologies

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Your stack

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