Expired tokens can be renewed without validating the account password

Exploitation

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

CVSS

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

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Impact In versions of the proxy from 2022-09-05 onwards (since 8c874c2ff3d503ac20c7d32f46e08547fcb9e23f), expired OAuth 2.0 client credentials grant (CCG) flow authorisation tokens could be renewed automatically without checking their validity against the original account configuration (i.e., the password that was set up when first creating an account in the proxy). An attacker with knowledge of valid account addresses and careful timing (specifically, attempting to log in during a period from 10 minutes prior to the token expiry time, but before a genuine login request is received) could use this issue to gain access to an account. This issue is only a security concern if you use the proxy with the CCG flow and no additional account secret encryption (see below). If this is the case, it is particularly important to update if you use the proxy in a publicly-accessible setting (i.e., it is available from the internet or across a network). To fix the issue you should switch to version…

Published by the source

19 Dec 2023, 23:12 UTC

Last modified by the source

28 Nov 2024, 05:40 UTC

Source last checked

26 Oct 2026, 13:12 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-9wgg-m99q-hhfc

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-9wgg-m99q-hhfc

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# Patch Next advisory brief: GHSA-9wgg-m99q-hhfc

Advisory: Expired tokens can be renewed without validating the account password
IDs: GHSA-9wgg-m99q-hhfc
Record: https://patchnext.com/advisories/ghsa-9wgg-m99q-hhfc (revision 2, source checked 26 Oct 2026, 13:12 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: emailproxy 2023.12.19. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI emailproxy: affected <= 2023.11.18; fixed in 2023.12.19

## Suggested inspection (read-only)
- `python -m pip show emailproxy`: 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 emailproxy.
- 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-9wgg-m99q-hhfc (OSV record GHSA-9wgg-m99q-hhfc lists affected ranges: PyPI emailproxy >=0 <2023.12.19 (fixed))
- Verified: https://github.com/advisories/GHSA-9wgg-m99q-hhfc (GitHub-reviewed advisory GHSA-9wgg-m99q-hhfc lists affected ranges: PyPI emailproxy >=0 <=2023.11.18)

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