CVE-2026-73136
Static memo configuration in mpp Tempo disables per-challenge attribution binding, enabling third-party replay
Description
Authentication Bypass by Capture-replay in ZenHive mpp allows an unauthenticated third party to obtain paid resources by replaying a transfer settled by an unrelated payer. MPP.Methods.Tempo normally binds a settled TIP-20 TransferWithMemo to the specific challenge under verification through an attribution nonce carried in the memo. When a static "memo" is configured in method_config, check_matched_memo_binding/3 returns the match unconditionally and that binding is skipped, leaving only token, recipient, amount and the static memo value to match on. The static memo is echoed in every unauthenticated 402 response and Tempo transfers are public, so an attacker can take any matching transfer paid by a legitimate customer, request a fresh challenge for the same route, and present that transaction hash as a type="hash" credential. The hash path performs no sender or signature check tying the presenter to the wallet that broadcast the transfer. This issue affects mpp: from 0.6.1 before 0.6.4.
INFO
Published Date :
Aug. 19, 2026, 6:17 p.m.
Last Modified :
Aug. 19, 2026, 7:17 p.m.
Remotely Exploit :
Yes !
Source :
6b3ad84c-e1a6-4bf7-a703-f496b71e49db
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 4.0 | HIGH | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db | ||||
| CVSS 4.0 | HIGH | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db |
Solution
- Update ZenHive mpp to version 0.6.4.
- Ensure method_config is not set to a static memo.
- Verify transfer binding logic.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-73136.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-73136 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-73136
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-73136 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-73136 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 19, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-73136', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-19T18:49:35.273666Z'} -
New CVE Received by 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
Aug. 19, 2026
Action Type Old Value New Value Added Affected [{'cpes': ['cpe:2.3:a:ZenHive:mpp:*:*:*:*:*:*:*:*'], 'repo': 'https://github.com/ZenHive/mpp', 'vendor': 'ZenHive', 'modules': ["'Elixir.MPP.Methods.Tempo'"], 'product': 'mpp', 'versions': [{'status': 'affected', 'version': '0.6.1', 'lessThan': '0.6.4', 'versionType': 'semver'}], 'packageURL': 'pkg:hex/mpp', 'packageName': 'mpp', 'programFiles': ['lib/mpp/methods/tempo.ex'], 'collectionURL': 'https://repo.hex.pm', 'defaultStatus': 'unaffected', 'programRoutines': [{'name': "'Elixir.MPP.Methods.Tempo':verify/2"}, {'name': "'Elixir.MPP.Methods.Tempo':validate_config!/1"}]}, {'cpes': ['cpe:2.3:a:ZenHive:mpp:*:*:*:*:*:*:*:*'], 'repo': 'https://github.com/ZenHive/mpp', 'vendor': 'ZenHive', 'modules': ["'Elixir.MPP.Methods.Tempo'"], 'product': 'mpp', 'versions': [{'status': 'affected', 'version': '542a525563c2fcedd670b593437deca81c6797a4', 'lessThan': '2207d7f456ae14c1d3fcacc6f635bf4f8cee1a34', 'versionType': 'git'}], 'packageURL': 'pkg:github/zenhive/mpp', 'packageName': 'zenhive/mpp', 'programFiles': ['lib/mpp/methods/tempo.ex'], 'collectionURL': 'https://github.com', 'defaultStatus': 'unaffected', 'programRoutines': [{'name': "'Elixir.MPP.Methods.Tempo':verify/2"}, {'name': "'Elixir.MPP.Methods.Tempo':validate_config!/1"}]}] Added Description Authentication Bypass by Capture-replay in ZenHive mpp allows an unauthenticated third party to obtain paid resources by replaying a transfer settled by an unrelated payer. MPP.Methods.Tempo normally binds a settled TIP-20 TransferWithMemo to the specific challenge under verification through an attribution nonce carried in the memo. When a static "memo" is configured in method_config, check_matched_memo_binding/3 returns the match unconditionally and that binding is skipped, leaving only token, recipient, amount and the static memo value to match on. The static memo is echoed in every unauthenticated 402 response and Tempo transfers are public, so an attacker can take any matching transfer paid by a legitimate customer, request a fresh challenge for the same route, and present that transaction hash as a type="hash" credential. The hash path performs no sender or signature check tying the presenter to the wallet that broadcast the transfer. This issue affects mpp: from 0.6.1 before 0.6.4. Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-294 Added Reference https://cna.erlef.org/cves/CVE-2026-73136.html Added Reference https://github.com/ZenHive/mpp/commit/2207d7f456ae14c1d3fcacc6f635bf4f8cee1a34 Added Reference https://github.com/ZenHive/mpp/security/advisories/GHSA-34g7-vx6g-82mq Added Reference https://osv.dev/vulnerability/EEF-CVE-2026-73136