CVE-2024-38521Public exploitNetwork attack vector

Inbox takeover via unsafe Jinja rendering

Published Jun 28, 2024 · Updated Aug 2, 2024

Stored XSS in Hush Line before 0.1.0 allows remote attackers to execute script in a recipient's Inbox through a crafted tip. The Inbox template applies Jinja2's safe filter to attacker-controlled message content, causing the browser to interpret injected HTML instead of escaping it. A recipient must open the stored message; with a separate CSP bypass, script can read the Inbox and change account security settings.

CVSS severity8.8
High
EPSS probability0.43%
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 Hush Line before 0.1.0 allows remote attackers to execute script in a recipient's Inbox through a crafted tip. The Inbox template applies Jinja2's safe filter to attacker-controlled message content, causing the browser to interpret injected HTML instead of escaping it. A recipient must open the stored message; with a separate CSP bypass, script can read the Inbox and change account security settings.

The record

CVE
CVE-2024-38521
Published
Jun 28, 2024
Updated
Aug 2, 2024
Vendor
Science & Design, Inc.
Product
Hush Line
Classifications
CWE-80, CWE-79, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 28, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=0 <0.1.0
  2. Affected versionversion=< 0.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Science & Design, Inc. · Hush Lineversion=0 <0.1.0; version=< 0.1.0

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
8.8GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-80Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1190Exploit Public-Facing Application

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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