CVE-2026-44546Network attack vector

ASGI header spoofing via WebSocket parser differential

Published Jun 3, 2026 · Updated Jun 3, 2026

Header smuggling in Daphne 4.2.0 through 4.2.1 allows remote attackers to spoof ASGI scope headers through WebSocket upgrades. Daphne rebuilds Twisted-parsed headers for Autobahn, whose splitlines() call treats six additional bytes as separators and creates attacker-supplied headers. Exploitation requires a crafted upgrade to reach Daphne and exposes data when an application trusts spoofable authentication, origin, or forwarding headers.

CVSS severity3.7
Low
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Header smuggling in Daphne 4.2.0 through 4.2.1 allows remote attackers to spoof ASGI scope headers through WebSocket upgrades. Daphne rebuilds Twisted-parsed headers for Autobahn, whose splitlines() call treats six additional bytes as separators and creates attacker-supplied headers. Exploitation requires a crafted upgrade to reach Daphne and exposes data when an application trusts spoofable authentication, origin, or forwarding headers.

The record

CVE
CVE-2026-44546
Published
Jun 3, 2026
Updated
Jun 3, 2026
Vendor
Django Software Foundation
Product
Daphne
Classifications
CWE-444, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 3, 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=4.2.0 <=4.2.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Django Software Foundation · Daphneversion=4.2.0 <=4.2.1

Published CVSS scores

3.7Django Software FoundationCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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')
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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