Vulnerability · Published Jun 3, 2026 · Assigned by DSF

CVE-2026-44545Unbounded WebSocket message and frame sizes can cause unauthenticated remote denial of service

Medium 5.3

In plain English

A medium-severity resource allocation without limits in daphne from djangoproject. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)0.3%top 74.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

daphne before 4.2.2 did not pass maxFramePayloadSize or maxMessagePayloadSize to Autobahn's WebSocketServerFactory. Because Autobahn defaults both values to 0 (unlimited), an unauthenticated remote attacker could send arbitrarily large WebSocket messages or frames, causing excessive memory consumption and a denial of service.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Alpine:v3.24	py3-daphne	4.2.3-r0	ALPINE-CVE-2026-44545
Debian:12	python-daphne	no fix listed	DEBIAN-CVE-2026-44545
Debian:13	python-daphne	4.1.2-2+deb13u1	DEBIAN-CVE-2026-44545
Debian:14	python-daphne	4.2.2-0.1	DEBIAN-CVE-2026-44545
PyPI	daphne	4.2.2	PYSEC-2026-213
PyPI	daphne	4.2.2	GHSA-rrc9-mx66-ffcm
Ubuntu:22.04:LTS	python-daphne	no fix listed	UBUNTU-CVE-2026-44545
Ubuntu:24.04:LTS	python-daphne	no fix listed	UBUNTU-CVE-2026-44545
Ubuntu:25.10	python-daphne	no fix listed	UBUNTU-CVE-2026-44545
Ubuntu:26.04:LTS	python-daphne	no fix listed	UBUNTU-CVE-2026-44545
Ubuntu:26.10	python-daphne	no fix listed	UBUNTU-CVE-2026-44545

Affected products (as reported)

Vendor	Product	Versions
djangoproject	daphne	4.2.0 – through 4.2.1

Weakness: CWE-770 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References

https://github.com/django/daphne/blob/main/CHANGELOG.txt release-notes