CVE-2026-89420
CVE.org · Published
- Record status
- Published
- Identifier year (not publication year)
- 2026
- Source publication
- Source updated
- Imported by cveboard
- Source snapshot
- cve_2026-10-24_midnight_baseline ·
CNA source text (English)
Session voucher adding no new funds is accepted without a charge in mpp, serving paid resources for free
Improper Validation of Specified Quantity in Input in ZenHive mpp allows a client holding an open payment channel to obtain paid resources without being charged. MPP.Session.Actions.accept_voucher/3 in lib/mpp/session/actions.ex treats a voucher whose cumulativeAmount equals the channel's already-accepted cumulative amount as an idempotent success, returning the channel unchanged without calling maybe_spend/2. The credential verifies, the protected resource is served, and spent and units stay where they were. Because the server issues a fresh challenge per request and the credential replay store keys on challenge id and payload, the same signed voucher can be re-presented under every new challenge, so one paid voucher yields an unbounded number of paid units. The path is reachable from any method built on MPP.Session.Method through the Plug, MCP, JSON-RPC and WebSocket transports. This issue affects mpp: from 0.14.0 before 0.16.2.
Scoped product and version facts
Fix information unknown; no fixed version is derived here. Missing information does not prove that no fix exists.
Exploitation unknown; this catalogue does not assess exploitation.
mpp
- Vendor
- ZenHive
- Product
- mpp
- Platforms
- Unknown
- Default status
unaffected- Package
- mpp
- Package collection
- https://repo.hex.pm
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| 0.14.0 | affected | semver | 0.16.2 | Unavailable | None listed |
mpp
- Vendor
- ZenHive
- Product
- mpp
- Platforms
- Unknown
- Default status
unaffected- Package
- zenhive/mpp
- Package collection
- https://github.com
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| 82df569c898be1137189e3648e1edb4af6363651 | affected | git | 7270edc1dcfb58250cc5ee812876609206564165 | Unavailable | None listed |