CVE-2026-55552Public exploitNetwork attack vectorHinoki check available

Host file disclosure via unnormalized static path

Published Aug 28, 2026 · Updated Aug 28, 2026

Path traversal in Yamcs before 5.12.0 allows remote attackers to read host files through unauthenticated static-file requests. StaticFileHandler.locateFile resolves the request path under each staticRoots entry but fails to normalize it and verify that its absolute form remains inside the root. A crafted path with traversal segments reaches any existing, non-hidden file readable by the Yamcs process; no account or user interaction is required.

CVSS severity7.5
High
EPSS probability0.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Path traversal in Yamcs before 5.12.0 allows remote attackers to read host files through unauthenticated static-file requests. StaticFileHandler.locateFile resolves the request path under each staticRoots entry but fails to normalize it and verify that its absolute form remains inside the root. A crafted path with traversal segments reaches any existing, non-hidden file readable by the Yamcs process; no account or user interaction is required.

The record

CVE
CVE-2026-55552
Published
Aug 28, 2026
Updated
Aug 28, 2026
Vendor
Space Applications Services
Product
Yamcs
Classifications
CWE-22, T1005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

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

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

  1. Affected versionversion=< 5.12.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Space Applications Services · Yamcsversion=< 5.12.0

Published CVSS scores

7.5GitHubCVSS:3.1/AV:N/AC:L/PR:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
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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