CVE-2026-53877: Django GIS GDALRaster Buffer Over-Read Vulnerability

Technical summary

The vulnerability exists in `django.contrib.gis.gdal.GDALRaster`, which incorrectly handles the buffer boundaries when instantiating GDALRaster objects from bytes input. The flaw is a CWE-805 buffer over-read that occurs when the `vsi_buffer` property is subsequently accessed on the malformed object. This can result in reading memory beyond the allocated buffer, potentially exposing adjacent memory contents, or triggering a segmentation fault that denies service. The issue requires network access but does not require authentication or user interaction to trigger.

Business impact

Organizations running Django applications with GIS functionality should assess exposure. A successful exploit could result in information disclosure (leaking sensitive data from server memory) or availability loss (application crash). The impact is most significant for web applications handling geographic data processing, mapping services, or location-based features. While the CVSS score is moderate, the combination of remote exploitability and memory disclosure potential warrants timely remediation, particularly if the affected Django instance processes untrusted geographic input.

Affected systems

Django 6.0.0 through 6.0.6 and Django 5.2.0 through 5.2.15 are confirmed affected. Django versions 5.0.x, 4.1.x, and 3.2.x (all unsupported) have not been formally evaluated but may be vulnerable. Any Django application using the `django.contrib.gis` module with GDALRaster construction from external bytes data is at risk.

Exploitability

The vulnerability requires network access but no credentials or user interaction. However, practical exploitation depends on the application's architecture: the attacker must influence the bytes input passed to GDALRaster construction. This is achievable in applications that accept geographic file uploads, process geographic data from APIs, or construct raster objects from untrusted sources. The CVSS vector (AC:H) reflects the somewhat elevated complexity of reliably triggering memory disclosure versus a guaranteed denial-of-service condition.

Remediation

Upgrade to Django 6.0.7 or later for the 6.0 series, and Django 5.2.16 or later for the 5.2 series. Organizations on unsupported versions (5.0.x, 4.1.x, 3.2.x) should prioritize migration to a supported release. As an interim control, restrict the sources of geographic data accepted by your application and validate file formats before passing them to GDALRaster.

Patch guidance

Django recommends upgrading to 6.0.7 (or newer in the 6.0.x line) or 5.2.16 (or newer in the 5.2.x line). Verify the exact patch version in the official Django security advisory before deployment. Test patched versions in a staging environment, particularly if your application heavily uses GIS functionality, to ensure no regressions in geographic data processing workflows. Organizations unable to upgrade immediately should implement network-level controls to restrict access to endpoints processing geographic data.

Detection guidance

Monitor application logs for exceptions or crashes when processing geographic data, particularly segmentation faults or unhandled exceptions within django.contrib.gis modules. If you have request logging, flag unusual geographic file uploads or requests with unexpected binary content. Review application code to identify all locations where GDALRaster is instantiated, especially those accepting external input. Intrusion detection systems should be configured to alert on suspicious patterns of geographic data submission followed by application errors.

Why prioritize this

Although the CVSS score is moderate (4.8), this vulnerability merits prompt attention because it combines remote exploitability with dual impact (information disclosure and denial of service). Organizations using Django GIS should prioritize this update within their standard patch cycle. The memory disclosure aspect is particularly concerning for applications handling sensitive geospatial data or running in regulated environments. Unsupported version users should accelerate their upgrade timeline.

Risk score, explained

The CVSS 3.1 score of 4.8 (MEDIUM) reflects a network-exploitable vulnerability with no authentication required, but elevated attack complexity (AC:H) due to the need for precise malformed input. The impact is limited scope with low confidentiality impact (memory disclosure) and low availability impact (potential crash). The moderate score should not obscure the real-world risk: information disclosure from memory is a serious concern, and the need for specialized input makes the attack less trivial but still feasible for motivated attackers.

Frequently asked questions