CVE-2026-48591Public exploit

Stored XSS via unescaped HTML attribute values

Published Jun 17, 2026 · Updated Jun 17, 2026

Stored XSS in Dave Thomas Earmark 1.4.1 and later allows context-dependent attackers to execute JavaScript through crafted Markdown. The _make_att1/2 function inserts link URL and title values between literal quotation marks without applying the escaping used for text nodes. A bare quotation mark closes the generated attribute, so JavaScript executes when a victim views HTML rendered from attacker-controlled Markdown.

CVSS severity4.8
Medium
EPSS probability0.13%
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 Dave Thomas Earmark 1.4.1 and later allows context-dependent attackers to execute JavaScript through crafted Markdown. The _make_att1/2 function inserts link URL and title values between literal quotation marks without applying the escaping used for text nodes. A bare quotation mark closes the generated attribute, so JavaScript executes when a victim views HTML rendered from attacker-controlled Markdown.

The record

CVE
CVE-2026-48591
Published
Jun 17, 2026
Updated
Jun 17, 2026
Vendor
Dave Thomas
Product
Earmark
Classifications
CWE-83, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 17, 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=1.4.1 <*
  2. Affected versionversion=8236a0570bd894b50e360da08131ec3294c20799 <*

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Dave Thomas · Earmarkversion=1.4.1 <*; version=8236a0570bd894b50e360da08131ec3294c20799 <*

Published CVSS scores

4.8Erlang Ecosystem FoundationCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/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.

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No observations available

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

Weakness, pattern, technique

CWE-83Improper Neutralization of Script in Attributes in a Web Page
T1203Exploitation for Client Execution

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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