How severe is GHSA-vv77-66rf-pm86?

No CVSS score has been assigned to GHSA-vv77-66rf-pm86 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-vv77-66rf-pm86?

GHSA-vv77-66rf-pm86 affects the following packages: mpp (Hex). Ecosystems affected: Hex.

How do I fix GHSA-vv77-66rf-pm86?

Update mpp to 0.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vv77-66rf-pm86 is resolved across your whole dependency graph.

How do I detect GHSA-vv77-66rf-pm86 in my Hex dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mpp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-vv77-66rf-pm86 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is GHSA-vv77-66rf-pm86 actively exploited in the wild?

No public exploit code has been indexed for GHSA-vv77-66rf-pm86 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-vv77-66rf-pm86?

GHSA-vv77-66rf-pm86 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 44th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-vv77-66rf-pm86?

GHSA-vv77-66rf-pm86 is classified as CWE-1284 (CWE-1284). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-vv77-66rf-pm86 published, and has it been updated?

GHSA-vv77-66rf-pm86 was published on September 25, 2026 and was last updated on September 25, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

💧 Hex

Not in CISA KEV

mpp vulnerable to Gas Draining with no limitGHSA-vv77-66rf-pm86

Fix: ZenHive/mpp@5d6338e

GHSA-vv77-66rf-pm86 is a CWE-1284 vulnerability in mpp. A fix is available for mpp — see the affected versions and patch details below.

Also known asCVE-2026-59695EEF-CVE-2026-59695

Published

Sep 25, 2026

Updated

Sep 25, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 23, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA’s SSVC triage for GHSA-vv77-66rf-pm86.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs44th percentile — riskier than 44% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

💧mpp

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Hex packages — download data is not available via public APIs for these ecosystems.

Description

Details

When the server acts as the fee_payer, the mpp Elixir 0.4.0 does not validate gas_limit, max_fee_per_gas and max_priority_fee_per_gas before cosigning the client's fee-payer transaction. A malicious client embeds arbitrarily large max_fee_per_gas and max_priority_fee_per_gas values in the signed envelope. The server cosigns and broadcasts — paying those inflated gas costs from its own wallet based on the effective_gas_price calculated from the high max_fee_per_gas and max_priority_fee_per_gas set by the client.

Vulnerable function: cosign_fee_payer/3 in transaction.ex around lines 229–262.

PoC

The PoC is provided below. It is configured to reproduce the attack on Tempo Moderate testnet within a Docker environment. Download the PoC and run:

unzip mpp_elixir_PoC.zip
cd mpp_elixir
docker build -t mpp-elixir-gasdrain .
docker run --rm mpp-elixir-gasdrain

There are more details in mpp_elixir/README.md

Impact

By draining the server's wallet, an attacker causes direct financial loss to the organization. Furthermore, if the server's funds are drained completely, legitimate clients will have their requests fail, as the server can no longer fund future transactions, effectively creating a Denial of Service (DoS) attack.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
💧Hex	`mpp`	≥ 0.2.0&&< 0.6.0	0.6.0`mix deps.update mpp`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mpp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mpp to 0.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vv77-66rf-pm86 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

### Details When the server acts as the fee_payer, the `mpp` Elixir 0.4.0 does not validate `gas_limit`, `max_fee_per_gas` and `max_priority_fee_per_gas` before cosigning the client's fee-payer transaction. A malicious client embeds arbitrarily large `max_fee_per_gas` and `max_priority_fee_per_gas` values in the signed envelope. The server cosigns and broadcasts — paying those inflated gas costs from its own wallet based on the `effective_gas_price` calculated from the high `max_fee_per_gas` and `max_priority_fee_per_gas` set by the client. **Vulnerable function:** `cosign_fee_payer/3` in [`t

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