CVE-2026-70646 aiosend: Deserialization of request body before signature verification (Pre-auth DoS) in webhook handler
Unauthenticated attackers can cause denial of service in aiosend by sending large JSON payloads that are parsed before signature verification.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-70646?
CVE-2026-70646 is a high-severity denial of service vulnerability in vovchic17 aiosend, published on 6 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
aiosend is a synchronous and asynchronous Crypto Pay API client. Pror to version 3.0.7, `WebhookHandler.feed_update()` deserializes the entire request body before verifying the HMAC signature. This allows an unauthenticated attacker to force expensive parsing of arbitrary JSON payloads that will ultimately be rejected, leading to unnecessary CPU and memory consumption. Version 3.0.7 fixes the issue. Some workarounds are available. Restrict request body size at the reverse proxy or web framework, rate-limit webhook endpoints, and/or reject oversized requests before JSON parsing.
Weakness: CWE-400
Which versions are affected by CVE-2026-70646?
3 open source packages ship an affected version, including aiosend.
| Package | Affected | Fixed in |
|---|---|---|
aiosend PyPI | All versions | 3.0.7 |
aiosend PyPI | All versions | 3.0.7 |
aiosend PyPI | All versions | 3.0.7 |
How do I fix CVE-2026-70646?
Upgrade aiosend to 3.0.7 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-2026-70646 being exploited?
There is no known exploitation of CVE-2026-70646 in the wild and no public exploit code.
Sources
Also known as GHSA-7m8f-hgjq-8gc9, PYSEC-2026-3626.