CVE-2026-77387: geopy Denial of Service Vulnerability

MODERATE
Advisory Identifier: GHSA-mhvh-fq92-pfmr
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CVSS 4.0
CWE-1333
Published
Advisory Summary

CVE-2026-77387 is a MODERATE (CVSS 4.0) denial of service vulnerability (CWE-1333: Inefficient Regular Expression Complexity) affecting geopy libraries in the PyPI ecosystem. The issue involves regular expression denial of service (redos) in geopy.point. Remediation is available by upgrading affected packages to version 2.5.0.

CVE-2026-77387 at a Glance

CVE Identifier CVE-2026-77387
GHSA Identifier GHSA-mhvh-fq92-pfmr
Severity MODERATE
CVSS v3.1 Base Score 4.0
CWE Classification CWE-1333: Inefficient Regular Expression Complexity
Affected Product geopy
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 4.0

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

Attack Vector Local (AV:L)
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-2026-77387

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

geopy fixed: 2.5.0 
pip install geopy>=2.5.0
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 geopy

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-77387, inspect your installed packages using pip:

pip show geopy

Analyze the terminal output to locate any version of geopy in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.5.0), your application is affected.

Note: The pip show geopy 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 geopy, 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

### Impact `geopy.Point` and `Point.from_string()` may take excessive CPU time when parsing long, malformed coordinate strings due to inefficient regular-expression behavior. The numeric Point constructor is not affected. Geocoders' `reverse` methods called with string inputs exercise the vulnerable path. Applications are affected when they pass attacker-controlled strings to these APIs without an appropriate length limit. Repeated requests may cause denial of service. ### Patches Fixed in geopy **2.5.0** by rejecting overly long (over 256 characters) coordinate strings before parsing. ### Workarounds Limit coordinate strings to a reasonable maximum length, such as 256 characters, before passing them to geopy.

CVE-2026-77387 Affected geopy Versions

1 component(s)
Fixed Versions:
2.5.0
Product / Package Ecosystem Affected Versions Fixed Version
geopy
pypi/geopy
PyPI
< 2.5.0
2.5.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/geopy/geopy/security/advisories/GHSA-mhvh-fq92-pfmr
NVD — CVE-2026-77387 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-77387
geopy Source Repository REPOSITORY
https://github.com/geopy/geopy/issues/608
geopy Source Repository REPOSITORY
https://github.com/geopy/geopy/pull/610
Security Fix Commit FIX COMMIT
https://github.com/geopy/geopy/commit/5d09fa843f90ec80788b61552539c9fd3ae6c528
geopy Source Repository REPOSITORY
https://github.com/geopy/geopy
geopy Release RELEASE
https://github.com/geopy/geopy/releases/tag/2.5.0

Frequently Asked Questions

What is CVE-2026-77387?
CVE-2026-77387 is a security vulnerability in geopy involving Regular Expression Denial of Service (ReDoS) in geopy.Point under CWE-1333: Inefficient Regular Expression Complexity.
Which geopy versions are affected?
Affected versions include releases prior to 2.5.0 across affected packages: geopy.
What version fixes CVE-2026-77387?
Upgrading to 2.5.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is geopy affected?
Yes, geopy is affected in releases prior to 2.5.0. Upgrade your dependency to 2.5.0 or later.
What is the CVSS score of CVE-2026-77387?
CVE-2026-77387 has a CVSS v3.1 base score of 4.0 (MODERATE) with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
What CWE is associated with CVE-2026-77387?
CVE-2026-77387 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-2026-77387?
Run the dependency tree command: 'pip show geopy'. 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-mhvh-fq92-pfmr",
  "modified" : "2026-10-02T22:38:14Z",
  "published" : "2026-10-02T22:38:14Z",
  "aliases" : [ "CVE-2026-77387" ],
  "summary" : "geopy: Regular Expression Denial of Service (ReDoS) in geopy.Point",
  "details" : "### Impact\n\n`geopy.Point` and `Point.from_string()` may take excessive CPU time when parsing long, malformed coordinate strings due to inefficient regular-expression behavior. The numeric Point constructor is not affected.\n\nGeocoders' `reverse` methods called with string inputs exercise the vulnerable path.\n\nApplications are affected when they pass attacker-controlled strings to these APIs without an appropriate length limit. Repeated requests may cause denial of service.\n\n### Patches\n\nFixed in geopy **2.5.0** by rejecting overly long (over 256 characters) coordinate strings before parsing.\n\n### Workarounds\n\nLimit coordinate strings to a reasonable maximum length, such as 256 characters, before passing them to geopy.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "geopy"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.5.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 2.4.1"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/geopy/geopy/security/advisories/GHSA-mhvh-fq92-pfmr"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-77387"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/geopy/geopy/issues/608"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/geopy/geopy/pull/610"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/geopy/geopy/commit/5d09fa843f90ec80788b61552539c9fd3ae6c528"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/geopy/geopy"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/geopy/geopy/releases/tag/2.5.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1333" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-02T22:38:14Z",
    "nvd_published_at" : "2026-10-01T17:17:31Z"
  }
}