TI-2026-60406 Aliases CVE-2026-89186 GHSA-4h6w-pvrh-g28p

mpp writes Payment-Receipt and Cache-Control before the wrapped application runs, letting…

LOW 29CWE-524Published 2026-09-16 · Updated 2026-09-16

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Attack requirements: Present
Impact type: —
Confidentiality · integrity · availability: Low · None · None
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

Use of Cache Containing Sensitive Information in ZenHive mpp allows a shared HTTP cache to store a paid response and serve it to clients that never paid. MPP.Plug.verify_credential in lib/mpp/plug.ex sets payment-receipt and cache-control: private on the connection before the wrapped application runs, and registers no register_before_send/2 callback. Plug.Conn.put_resp_header/3 replaces an existing header, so a mounting application that sets its own cache-control on the paid resource (for example public, max-age=3600) silently overrides the private the library relies on, and a CDN or reverse proxy can then store the paid 200 together with its Payment-Receipt and serve both to unpaid clients. The library-level guarantee is therefore defeatable by the application it protects. For the same reason a downstream non-2xx response still carried Payment-Receipt, issuing a receipt for a response that delivered no resource. This issue affects mpp: from 0.1.0 before 0.16.2.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00524 44th percentileScored 2026-11-07

Fix Fixed mpp (ZenHive): 0.16.2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
ZenHive	mpp	0.1.0 to before 0.16.2	0.16.2	Patch available	CNA

mpp VendorZenHive Affected 0.1.0 to before 0.16.2 Fixed in 0.16.2 Patch available CNA

CPE names CNA · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:ZenHive:mpp::::::::	—	—	—

cpe:2.3:a:ZenHive:mpp:*:*:*:*:*:*:*:* Versions — — ·—

Remediation

Fix · CNA mpp (ZenHive) Fixed in 0.16.2

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

Release · 2026-09-16
ZenHive mpp 0.16.2
2 records Highest priority Priority LOW 2 LOW
Other records, highest priority first
- TI-2026-60087 mpp Tempo keys its pre-broadcast dedup reserve on the caller-supplied transaction…Priority LOW 29
Show all 2 records →

Timeline

2026-10-02 Threatist record created from CVE-2026-89186
2026-10-03 Alias added: GHSA-4h6w-pvrh-g28p

References

Patch 1

Fix commit 2fd91a5 in ZenHive/mpp

Advisory 1

GitHub Advisory

Other 3

TI-2026-42571 Unbounded max_fee_per_gas in mpp Tempo fee-payer enables single-request wallet drain CVSS 4.0HIGH 8.3
TI-2026-42570 Unbounded access list in mpp Tempo fee-payer inflates gas cost per payment CVSS 4.0HIGH 8.3
TI-2026-42392 Missing gas_limit validation in mpp Tempo fee-payer enables wallet drain CVSS 4.0HIGH 8.2
TI-2026-60473 Session voucher adding no new funds is accepted without a charge in mpp, serving paid resources for free CVSS 4.0HIGH 7.1
TI-2026-47746 On-chain transfer proof is not single-use in mpp EVM payment method, enabling cross-challenge replay CVSS 4.0HIGH 8.7
TI-2026-51635 Resource allocation without limits in ZenHive mpp CVSS 4.0HIGH 8.3

See all 12 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences