CVE-2025-27508Network attack vector

Integrity bypass via exposed weak checksum defaults

Published Mar 5, 2025 · Updated Mar 7, 2025

Risky cryptography in National Security Agency Emissary before 8.24.0 allows attackers to bypass integrity checks with hash collisions. Public ChecksumCalculator constructors default to SHA-1, enable CRC32, and expose KFF similarity hashing for use outside its intended package. Exploitation requires consuming code to treat these outputs as cryptographically secure integrity or authentication values.

CVSS severity7.5
High
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Risky cryptography in National Security Agency Emissary before 8.24.0 allows attackers to bypass integrity checks with hash collisions. Public ChecksumCalculator constructors default to SHA-1, enable CRC32, and expose KFF similarity hashing for use outside its intended package. Exploitation requires consuming code to treat these outputs as cryptographically secure integrity or authentication values.

The record

CVE
CVE-2025-27508
Published
Mar 5, 2025
Updated
Mar 7, 2025
Vendor
National Security Agency
Product
Emissary
Classifications
CWE-327, T1565
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 5, 2025CVE publishedPublication date reported by the CVE source.
  2. Mar 7, 2025Record 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=< 8.24.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

National Security Agency · Emissaryversion=< 8.24.0

Published CVSS scores

7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/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 exploitUnconfirmed

Weakness, pattern, technique

CWE-327Use of a Broken or Risky Cryptographic Algorithm
T1565Data Manipulation

Public exploit references

No public exploit references are available in this record.

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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