CVE-2023-49798Network attack vector

Duplicate subcall execution via repeated delegatecall

Published Dec 8, 2023 · Updated Aug 2, 2024

Improper control flow in OpenZeppelin Contracts 4.9.4 allows remote attackers to execute each Multicall subcall twice. A merge-conflict resolution duplicated Address.functionDelegateCall inside Multicall.sol's loop, so each data element is delegated once with raw calldata and again with appended context. A contract must inherit and expose the affected Multicall implementation; invoking a batch can then repeat state-changing operations, including asset transfers.

CVSS severity5.9
Medium
EPSS probability0.54%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper control flow in OpenZeppelin Contracts 4.9.4 allows remote attackers to execute each Multicall subcall twice. A merge-conflict resolution duplicated Address.functionDelegateCall inside Multicall.sol's loop, so each data element is delegated once with raw calldata and again with appended context. A contract must inherit and expose the affected Multicall implementation; invoking a batch can then repeat state-changing operations, including asset transfers.

The record

CVE
CVE-2023-49798
Published
Dec 8, 2023
Updated
Aug 2, 2024
Vendor
OpenZeppelin
Product
OpenZeppelin Contracts
Classifications
CWE-670
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 8, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion== 4.9.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenZeppelin · OpenZeppelin Contractsversion== 4.9.4

Published CVSS scores

5.9GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-670Always-Incorrect Control Flow Implementation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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