CVE-2026-6807Public exploit

Local file disclosure via external entity resolution

Published Apr 28, 2026 · Updated Apr 28, 2026

XXE in the session importer of National Security Agency GRASSMARLIN 3.2.1 allows local users to read host files via crafted session data. Opening a stored session passes its XML to a parser that resolves attacker-supplied external DTD entities and sends arbitrary local-file contents to an HTTP host. Exploitation requires low-privileged local access and the bundled older Java runtime; the demonstrated impact is file disclosure without data modification or service interruption.

CVSS severity5.5
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

XXE in the session importer of National Security Agency GRASSMARLIN 3.2.1 allows local users to read host files via crafted session data. Opening a stored session passes its XML to a parser that resolves attacker-supplied external DTD entities and sends arbitrary local-file contents to an HTTP host. Exploitation requires low-privileged local access and the bundled older Java runtime; the demonstrated impact is file disclosure without data modification or service interruption.

The record

CVE
CVE-2026-6807
Published
Apr 28, 2026
Updated
Apr 28, 2026
Vendor
National Security Agency
Product
GRASSMARLIN
Classifications
CWE-611, T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 28, 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?

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  1. Affected versionversion=All versions

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

National Security Agency · GRASSMARLINversion=All versions

Published CVSS scores

5.5ICS-CERTCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-611Improper Restriction of XML External Entity Reference
T1005Data from Local System

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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