GHSA-7M8F-HGJQ-8GC9

Vulnerability Description

In aiosend/webhook/base.py, the WebhookHandler.feed_update() method performs full deserialization of the incoming JSON via Pydantic before verifying the HMAC signature. Anyone can send a request with an arbitrary body, the server will parse it, spend CPU and memory, and only then reject it.

Vulnerable Code

# aiosend/webhook/base.py, feed_update()
update = Update.model_validate(body, context={"client": self})  #  parsing, always
if not self._check_signature(body, headers):                    #  auth, too late
    return False

Additional aggravating factor: CryptoPayObject is declared with ConfigDict(extra="allow"), all arbitrary fields from the body are stored in memory without any limits.

Minimal PoC

Requests with deliberately invalid signatures (zero credentials):

All requests were rejected, but the server already performed parsing for each one. 10 parallel threads with 5 MB bodies = >75 ms of CPU spent on requests that will never be authorized.

Affected Components

• aiosend/webhook/base.py, WebhookHandler.feed_update()
• aiosend/types/base.py, CryptoPayObject (extra="allow")
• All adapters: AiohttpManager, FastAPIManager, FlaskManager

Exploitation Conditions

• Attacker: anyone with network access to the webhook endpoint
• Authentication: not required
• Body size limit: absent at the library level (Flask and FastAPI have no default limit)

The advisory was translated using Copilot.

Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.

GHSA-7M8F-HGJQ-8GC9 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.0.6); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is GHSA-7M8F-HGJQ-8GC9? GHSA-7M8F-HGJQ-8GC9 is a high-severity uncontrolled resource consumption vulnerability in aiosend (pip), affecting versions < 3.0.6. It is fixed in 3.0.6. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
2. How severe is GHSA-7M8F-HGJQ-8GC9? GHSA-7M8F-HGJQ-8GC9 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of aiosend are affected by GHSA-7M8F-HGJQ-8GC9? aiosend (pip) versions < 3.0.6 is affected.
4. Is there a fix for GHSA-7M8F-HGJQ-8GC9? Yes. GHSA-7M8F-HGJQ-8GC9 is fixed in 3.0.6. Upgrade to this version or later.
5. Is GHSA-7M8F-HGJQ-8GC9 exploitable, and should I be worried? Whether GHSA-7M8F-HGJQ-8GC9 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether GHSA-7M8F-HGJQ-8GC9 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix GHSA-7M8F-HGJQ-8GC9? Upgrade aiosend to 3.0.6 or later.