CVE-2026-40481 monetr: Unauthenticated Stripe webhook reads attacker-sized request bodies before signature validation
Unauthenticated attackers can cause denial of service in monetr by sending oversized payloads to the Stripe webhook endpoint before signature validation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-40481?
CVE-2026-40481 is a high-severity denial of service vulnerability in monetr, published on 17 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
monetr is a budgeting application for recurring expenses. In versions 1.12.3 and below, the public Stripe webhook endpoint buffers the entire request body into memory before validating the Stripe signature. A remote unauthenticated attacker can send oversized POST payloads to cause uncontrolled memory growth, leading to denial of service. The issue affects deployments with Stripe webhooks enabled and is mitigated if an upstream proxy enforces a request body size limit. This issue has been fixed in version 1.12.4.
Weakness: CWE-400
Which versions are affected by CVE-2026-40481?
3 open source packages ship an affected version, including github.com/monetr/monetr. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/monetr/monetr Go | All versions | 1.12.4 |
github.com/monetr/monetr Go | All versions | 1.12.4 |
github.com/monetr/monetr Go | All versions | 1.12.4 |
Products include Monetr Monetr.
How do I fix CVE-2026-40481?
Upgrade github.com/monetr/monetr to 1.12.4 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-40481 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40481 exists.
Other vulnerabilities in monetr
Sources
Also known as GHSA-v7xq-3wx6-fqc2, GO-2026-5654.