lib/anubis: actually check the result with the correct difficulty (#180)

* cmd/anubis actually check the result with the correct difficulty

* chore: changelog

* test(cmd/anubis): make test check for difficulty

* lib: add regression test for CVE-2025-24369

Signed-off-by: Xe Iaso <me@xeiaso.net>

* bump VERSION and CHANGELOG

Tracks #181

Signed-off-by: Xe Iaso <me@xeiaso.net>

---------

Signed-off-by: Xe Iaso <me@xeiaso.net>
Co-authored-by: Xe Iaso <me@xeiaso.net>

docs/docs/CHANGELOG.md

@@ -10,6 +10,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+
 - Added a periodic cleanup routine for the decaymap that removes expired entries, ensuring stale data is properly pruned.
 - Added a no-store Cache-Control header to the challenge page
 - Hide the directory listings for Anubis' internal static content
@@ -28,6 +29,18 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fixed a typo in the challenge page title.
 - Disabled running integration tests on Windows hosts due to it's reliance on posix features (see [#133](https://github.com/TecharoHQ/anubis/pull/133#issuecomment-2764732309)).
 
+## v1.15.1
+
+Zenos yae Galvus: Echo 1
+
+Fixes a recurrence of [CVE-2025-24369](https://github.com/Xe/x/security/advisories/GHSA-56w8-8ppj-2p4f)
+due to an incorrect logic change in a refactor. This allows an attacker to mint a valid
+access token by passing any SHA-256 hash instead of one that matches the proof-of-work
+test.
+
+This case has been added as a regression test. It was not when CVE-2025-24369 was released
+due to the project not having the maturity required to enable this kind of regression testing.
+
 ## v1.15.0
 
 Zenos yae Galvus