CVE-2026-44545: daphne Unauthenticated Attackers Can Cause Excessive Vulnerability

MODERATE
Advisory Identifier: GHSA-rrc9-mx66-ffcm
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CVSS 5.3
CWE-770
Published
Advisory Summary

CVE-2026-44545 is a MODERATE (CVSS 5.3) unauthenticated attackers can cause excessive vulnerability (CWE-770: Allocation of Resources Without Limits or Throttling) affecting daphne libraries in the PyPI ecosystem. The issue involves unauthenticated attackers can cause excessive memory consumption by sending arbitrarily large websocket messages/frames. Remediation is available by upgrading affected packages to version 4.2.2.

CVE-2026-44545 at a Glance

CVE Identifier CVE-2026-44545
GHSA Identifier GHSA-rrc9-mx66-ffcm
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-770: Allocation of Resources Without Limits or Throttling
Affected Product daphne
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 5.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability Low (A:L)

How to Fix CVE-2026-44545

To remediate this vulnerability, upgrade all affected daphne dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

daphne fixed: 4.2.2 
pip install daphne>=4.2.2
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show daphne

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-44545, inspect your installed packages using pip:

pip show daphne

Analyze the terminal output to locate any version of daphne in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.2.2), your application is affected.

Note: The pip show daphne command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-770: Allocation of Resources Without Limits or Throttling, where the product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated. In daphne, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2026-44545 Affected daphne Versions

1 component(s)
Fixed Versions:
4.2.2
Product / Package Ecosystem Affected Versions Fixed Version
daphne
pypi/daphne
PyPI
< 4.2.2
4.2.2

References

NVD — CVE-2026-44545 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-44545
daphne Source Repository REPOSITORY
https://github.com/django/daphne
daphne Source Repository REPOSITORY
https://github.com/django/daphne/blob/main/CHANGELOG.txt
daphne Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/daphne/PYSEC-2026-213.yaml

Frequently Asked Questions

What is CVE-2026-44545?
CVE-2026-44545 is a security vulnerability in daphne involving Unauthenticated attackers can cause excessive memory consumption by sending arbitrarily large WebSocket messages/frames under CWE-770: Allocation of Resources Without Limits or Throttling.
Which daphne versions are affected?
Affected versions include releases prior to 4.2.2 across affected packages: daphne.
What version fixes CVE-2026-44545?
Upgrading to 4.2.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is daphne affected?
Yes, daphne is affected in releases prior to 4.2.2. Upgrade your dependency to 4.2.2 or later.
What is the CVSS score of CVE-2026-44545?
CVE-2026-44545 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
What CWE is associated with CVE-2026-44545?
CVE-2026-44545 is classified under CWE-770: Allocation of Resources Without Limits or Throttling (The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.).
How can I check PyPI dependencies for CVE-2026-44545?
Run the dependency tree command: 'pip show daphne'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-rrc9-mx66-ffcm",
  "modified" : "2026-07-11T22:53:33Z",
  "published" : "2026-06-03T15:30:42Z",
  "aliases" : [ "CVE-2026-44545" ],
  "summary" : "daphne: Unauthenticated attackers can cause excessive memory consumption by sending arbitrarily large WebSocket messages/frames",
  "details" : "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "daphne"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "4.2.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-44545"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/django/daphne"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/django/daphne/blob/main/CHANGELOG.txt"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/daphne/PYSEC-2026-213.yaml"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-770" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-11T22:53:32Z",
    "nvd_published_at" : "2026-06-03T14:16:43Z"
  }
}