Security readout for executives and security teams
Plain-English summary
CVE-2026-59695 lets an unauthenticated client make a ZenHive mpp fee-payer service accept extreme gas-fee values. If the service sponsors gas, one crafted request can exhaust the sponsoring wallet, stopping legitimate sponsored payments. The issue affects mpp versions from 0.2.0 before 0.6.0.
Executive priority
Treat as high priority for any service that sponsors blockchain gas fees. The main business risk is direct financial loss from a drained fee-payer wallet and payment-service disruption. Prioritize internet-reachable or customer-facing fee-payer deployments first.
Technical view
In mpp Tempo fee-payer mode, MPP.Tempo.Transaction.cosign_fee_payer/3 re-signs client-supplied 0x76 AASigned envelope base fields, including max_fee_per_gas and max_priority_fee_per_gas, without bounding them. The broadcast transaction can charge inflated effective gas price to the fee-payer wallet. CVSS 4.0 score is 8.3, CWE-1284.
Likely exposure
Exposure is limited to ZenHive mpp deployments using affected versions and configured with fee_payer: true. Systems not sponsoring gas through mpp, or running 0.6.0 or later, are not indicated as affected by the provided sources.
Exploitation context
The CVE record describes unauthenticated remote exploitation with low attack complexity, but CISA KEV is false and no provided source claims active exploitation. Practical impact requires a reachable fee-payer service and a funded sponsor wallet.
Researcher notes
The vulnerability is an input-bound validation failure, not a key compromise. Focus assessment on transaction co-signing paths and whether client-controlled gas-fee ceilings are accepted. Evidence provided identifies a patch commit and fixed version boundary, but does not include proof of active exploitation.
Mitigation direction
- Upgrade ZenHive mpp to version 0.6.0 or later.
- Review the vendor advisory and patch commit for implementation details.
- If upgrade is delayed, consider disabling fee-payer mode where operationally acceptable.
- Monitor and limit exposure of fee-payer wallets until remediated.
Validation and detection
- Inventory applications using ZenHive mpp.
- Confirm mpp versions are not 0.2.0 through before 0.6.0.
- Check whether fee_payer: true is enabled.
- Review fee-payer wallet history for unexplained rapid depletion.
- Verify deployed code includes the referenced patch or fixed release.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-1284: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-59695 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.3 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N——EEFVulnerability scoring details
Base CVSS 4.0 score
8.3HighVector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/ZenHive/mpp/security/advisories/GHSA-vv77-66rf-pm86CVE reference, EEF · vendor-advisory, related
- https://cna.erlef.org/cves/CVE-2026-59695.htmlCVE reference, EEF · related
- https://osv.dev/vulnerability/EEF-CVE-2026-59695CVE reference, EEF · related
- https://github.com/ZenHive/mpp/commit/5d6338e2334084c5f2a78cfcca474830733ed7e8CVE reference, EEF · patch
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Validation of Specified Quantity in Input
Improper Validation of Specified Quantity in Input represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.