CVE-2025-12874Network attack vector

Unauthenticated request smuggling via CL.TE parsing

Published Dec 19, 2025 · Updated Dec 19, 2025

HTTP request smuggling in Quest Coexistence Manager for Notes 3.8.2045 allows remote attackers to manipulate Free/Busy Connector traffic. The connector inconsistently interprets requests containing both Content-Length and Transfer-Encoding headers, causing different HTTP agents to disagree on CL.TE message boundaries. Exploitation requires a network path with disagreeing HTTP agents and allows access-control bypass, cache poisoning, session hijacking, or unintended internal requests.

CVSS severity6.3
Medium
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

HTTP request smuggling in Quest Coexistence Manager for Notes 3.8.2045 allows remote attackers to manipulate Free/Busy Connector traffic. The connector inconsistently interprets requests containing both Content-Length and Transfer-Encoding headers, causing different HTTP agents to disagree on CL.TE message boundaries. Exploitation requires a network path with disagreeing HTTP agents and allows access-control bypass, cache poisoning, session hijacking, or unintended internal requests.

The record

CVE
CVE-2025-12874
Published
Dec 19, 2025
Updated
Dec 19, 2025
Vendor
Quest Software
Product
Coexistence Manager for Notes
Classifications
CWE-444, CAPEC-33, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 19, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 19, 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=3.8.2045

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Quest Software · Coexistence Manager for Notesversion=3.8.2045

Published CVSS scores

6.3Security Risk AdvisorsCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA: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 exploitUnconfirmed

Weakness, pattern, technique

CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
CAPEC-33HTTP Request Smuggling
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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