CVE-2026-34416Public exploitNetwork attack vector

Browser script execution via unescaped project parameter

Published Jun 9, 2026 · Updated Jun 9, 2026

Reflected XSS in OSCAL-GUI allows remote attackers to execute JavaScript in a victim's browser through a crafted project URL. The oscal.php response inserts the project request parameter into the body onload handler without context-appropriate escaping, allowing input to terminate the JavaScript string and HTML attribute. A victim must visit the attacker-crafted link; the resulting script runs in the OSCAL-GUI origin and can read or alter browser-accessible application data.

CVSS severity5.1
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in OSCAL-GUI allows remote attackers to execute JavaScript in a victim's browser through a crafted project URL. The oscal.php response inserts the project request parameter into the body onload handler without context-appropriate escaping, allowing input to terminate the JavaScript string and HTML attribute. A victim must visit the attacker-crafted link; the resulting script runs in the OSCAL-GUI origin and can read or alter browser-accessible application data.

The record

CVE
CVE-2026-34416
Published
Jun 9, 2026
Updated
Jun 9, 2026
Vendor
Brian Ruf
Product
OSCAL-GUI
Classifications
CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 9, 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=0 <=c989c4bd5a68f2621a81654e9250246539a28d5a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Brian Ruf · OSCAL-GUIversion=0 <=c989c4bd5a68f2621a81654e9250246539a28d5a

Published CVSS scores

5.1VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
6.1VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/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.

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')
T1189Drive-by Compromise

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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