CVE-2022-35961Network attack vector

Replay-protection bypass via alternate signature encoding

Published Aug 14, 2022 · Updated Apr 23, 2025

Signature malleability in OpenZeppelin Contracts 4.1.0 through 4.7.2 allows remote attackers to bypass signature replay protection. The bytes overloads of ECDSA.recover and ECDSA.tryRecover accept equivalent 65-byte and 64-byte EIP-2098 encodings for the same signed message. The bypass requires a consuming contract to mark the signature bytes themselves as used rather than tracking the signed message or a nonce.

CVSS severity7.9
High
EPSS probability0.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Signature malleability in OpenZeppelin Contracts 4.1.0 through 4.7.2 allows remote attackers to bypass signature replay protection. The bytes overloads of ECDSA.recover and ECDSA.tryRecover accept equivalent 65-byte and 64-byte EIP-2098 encodings for the same signed message. The bypass requires a consuming contract to mark the signature bytes themselves as used rather than tracking the signed message or a nonce.

The record

CVE
CVE-2022-35961
Published
Aug 14, 2022
Updated
Apr 23, 2025
Vendor
OpenZeppelin
Product
OpenZeppelin Contracts
Classifications
CWE-354
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 14, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 2025Record 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=>= 4.1.0, < 4.7.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OpenZeppelin · OpenZeppelin Contractsversion=>= 4.1.0, < 4.7.3

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
7.9GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:L

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-354Improper Validation of Integrity Check Value

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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