CVE-2026-54635 pytonapi has a Webhook Custom Path Authentication Bypass
An unauthenticated attacker can bypass webhook authentication in the pytonapi library by using a custom path, allowing them to trigger victim-defined handlers with forged payloads.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-54635?
CVE-2026-54635 is a high-severity authentication bypass vulnerability in nessshon tonapi, published on 28 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
pytonapi is a Python SDK for TONAPI that provides REST API, streaming, and webhook access to the TON blockchain. From 2.0.0 to 2.2.0, TonapiWebhookDispatcher fails to validate the Authorization header when a webhook handler is registered with the documented path argument, because setup() stores bearer tokens only under the default suffix paths and never adds the custom path to the token map, so self._tokens.get(path) returns None and the authentication guard is skipped. An unauthenticated remote attacker can POST forged payloads to the custom webhook endpoint and trigger victim-defined handlers. This issue is fixed in version 2.2.1.
Weakness: CWE-287
Which versions are affected by CVE-2026-54635?
3 open source packages ship an affected version, including pytonapi.
| Package | Affected | Fixed in |
|---|---|---|
pytonapi PyPI | From 2.0.0 | 2.2.1 |
pytonapi PyPI | From 2.0.0 | 2.2.1 |
pytonapi PyPI | From 2.0.0 | 2.2.1 |
How do I fix CVE-2026-54635?
Upgrade pytonapi to 2.2.1 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-54635 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-54635 exists.
Sources
Also known as GHSA-3fcr-jvgp-7f58, PYSEC-2026-3614.