CVE-2025-54796: Copyparty Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-5662-2rj7-f2v6
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CVSS 7.5
CWE-1333
Published
Advisory Summary

CVE-2025-54796 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-1333: Inefficient Regular Expression Complexity) affecting Copyparty libraries in the PyPI ecosystem. The issue involves copyparty allows regex denial of service (redos) in the upload listing. Remediation is available by upgrading affected packages to version 1.18.9.

CVE-2025-54796 at a Glance

CVE Identifier CVE-2025-54796
GHSA Identifier GHSA-5662-2rj7-f2v6
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-1333: Inefficient Regular Expression Complexity
Affected Product Copyparty
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.5

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:H).

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 High (A:H)

How to Fix CVE-2025-54796

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

copyparty fixed: 1.18.9 
pip install copyparty>=1.18.9
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 copyparty

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2025-54796, inspect your installed packages using pip:

pip show copyparty

Analyze the terminal output to locate any version of Copyparty in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.18.9), your application is affected.

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

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-1333: Inefficient Regular Expression Complexity, where the product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential. In Copyparty, 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

### Summary The `filter` parameter for the "Recent uploads" page allows arbitrary Regexes. If this feature is enabled (which is the default), an attacker can craft a filter which deadlocks the server. ### PoC `https://127.0.0.1:3923/?ru&filter=(.+)+x` ### Impact The server becomes fully inaccessible for a long time.

CVE-2025-54796 Affected Copyparty Versions

1 component(s)
Fixed Versions:
1.18.9
Product / Package Ecosystem Affected Versions Fixed Version
copyparty
pypi/copyparty
PyPI
< 1.18.9
1.18.9

References

Copyparty Source Repository REPOSITORY
https://github.com/9001/copyparty
GitHub Advisory / Wiki ADVISORY
https://github.com/9001/copyparty/security/advisories/GHSA-5662-2rj7-f2v6
NVD — CVE-2025-54796 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-54796
Security Fix Commit FIX COMMIT
https://github.com/9001/copyparty/commit/09910ba80784c3980947d92f45db696398c0fd83
Copyparty Release RELEASE
https://github.com/9001/copyparty/releases/tag/v1.18.9

Frequently Asked Questions

What is CVE-2025-54796?
CVE-2025-54796 is a security vulnerability in Copyparty involving copyparty allows Regex Denial of Service (ReDoS) in the upload listing under CWE-1333: Inefficient Regular Expression Complexity.
Which Copyparty versions are affected?
Affected versions include releases prior to 1.18.9 across affected packages: copyparty.
What version fixes CVE-2025-54796?
Upgrading to 1.18.9 (or the latest patched release for your respective branch) resolves the vulnerability.
Is copyparty affected?
Yes, copyparty is affected in releases prior to 1.18.9. Upgrade your dependency to 1.18.9 or later.
What is the CVSS score of CVE-2025-54796?
CVE-2025-54796 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2025-54796?
CVE-2025-54796 is classified under CWE-1333: Inefficient Regular Expression Complexity (The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.).
How can I check PyPI dependencies for CVE-2025-54796?
Run the dependency tree command: 'pip show copyparty'. 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-5662-2rj7-f2v6",
  "modified" : "2025-08-04T15:22:23Z",
  "published" : "2025-08-04T15:22:23Z",
  "aliases" : [ "CVE-2025-54796" ],
  "summary" : "copyparty allows Regex Denial of Service (ReDoS) in the upload listing",
  "details" : "### Summary\nThe `filter` parameter for the \"Recent uploads\" page allows arbitrary Regexes. If this feature is enabled (which is the default), an attacker can craft a filter which deadlocks the server.\n\n### PoC\n`https://127.0.0.1:3923/?ru&filter=(.+)+x`\n\n### Impact\nThe server becomes fully inaccessible for a long time.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "copyparty"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.18.9"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.18.8"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/9001/copyparty/security/advisories/GHSA-5662-2rj7-f2v6"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-54796"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/9001/copyparty/commit/09910ba80784c3980947d92f45db696398c0fd83"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/9001/copyparty"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/9001/copyparty/releases/tag/v1.18.9"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1333" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-08-04T15:22:23Z",
    "nvd_published_at" : "2025-08-02T00:15:26Z"
  }
}