axonflow-sdk-python: Webhook signing-key (HMAC-SHA256) not exposed by SDK type, preventing signature verification

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.9 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary The AxonFlow SDK's WebhookSubscription (or equivalent) type did not expose the HMAC-SHA256 signing key returned by the platform's CreateWebhook endpoint. Without access to the secret through the typed SDK API, callers had no path to verify the X-AxonFlow-Signature header on incoming webhook deliveries. Affected callers had two unsatisfactory options: 1. Skip signature verification entirely — accepting any payload from any source that knew the webhook URL. 2. Hand-parse the raw HTTP JSON response to extract the secret, bypassing the type-safe SDK surface. This advisory is filed across all four AxonFlow SDKs (Go, Python, TypeScript, Java) because the same defect and the same fix landed in each. Affected versions Versions 6.6.2 and below. Impact A webhook receiver using the SDK's typed API to handle inbound deliveries had no path to authenticate the source of incoming payloads. An attacker who learned the webhook URL — through misconfiguration, log leakage, observable network…

Published by the source

6 May 2026, 23:14 UTC

Last modified by the source

6 May 2026, 23:37 UTC

Source last checked

26 Oct 2026, 13:41 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-7f4h-6264-89fr

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-7f4h-6264-89fr

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: GHSA-7f4h-6264-89fr

Advisory: axonflow-sdk-python: Webhook signing-key (HMAC-SHA256) not exposed by SDK type, preventing signature verification
IDs: GHSA-7f4h-6264-89fr
Record: https://patchnext.com/advisories/ghsa-7f4h-6264-89fr (revision 2, source checked 26 Oct 2026, 13:41 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: axonflow 6.7.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI axonflow: affected < 6.7.0; fixed in 6.7.0

## Suggested inspection (read-only)
- `python -m pip show axonflow`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on axonflow.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-7f4h-6264-89fr (OSV record GHSA-7f4h-6264-89fr lists affected ranges: PyPI axonflow >=0 <6.7.0 (fixed))
- Verified: https://github.com/advisories/GHSA-7f4h-6264-89fr (GitHub-reviewed advisory GHSA-7f4h-6264-89fr lists affected ranges: PyPI axonflow >=0 <6.7.0)

Commands are suggestions: review each one before running it.