CVE-2024-45056: zksolc is a Solidity compiler for ZKsync

Q: How do I fix CVE-2024-45056?

zksolc: upgrade to 1.5.3. Exact commands for each OS are on this page.

Q: Is CVE-2024-45056 being exploited?

CVE-2024-45056 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2024-45056 affect?

CVE-2024-45056 affects zksolc. Severity is medium (CVSS 5.9). zksolc is a Solidity compiler for ZKsync. All LLVM versions since 2015 fold `(xor (shl 1, x), -1)` to `(rotl ~1, x)` if run with optimizations enabled. Here `~1` is generated as an unsigned 64 bits number (`2^64-1`). This number is zero-ext

Q: How urgent is CVE-2024-45056?

Priority 34/100. Remotely exploitable, no login, no user action

Routine

MEDIUM 5.9REMOTEUPGRADE

CVE-2024-45056 is a medium-severity flaw (CVSS 5.9) affecting zksolc. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

zksolc is a Solidity compiler for ZKsync. All LLVM versions since 2015 fold `(xor (shl 1, x), -1)` to `(rotl ~1, x)` if run with optimizations enabled. Here `~1` is generated as an unsigned 64 bits number (`2^64-1`). This number is zero-extended to 256 bits on EraVM target while it should have been sign-extended. Thus instead of producing `roti 2^256 - 1, x` the compiler produces `rotl 2^64 - 1, x`. Analysis has shown that no contracts were affec

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 65%)
CISA exploited list	No
Weakness	CWE-682
Published	2024-08-29
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: matter-labs

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2024-08-29 17:15 UTCPublished CVE record published
2026-06-17 07:53 UTCUpdated Record last modified

matter-labs zksolc UPGRADE

Affected: < 1.5.3

Fixed in: 1.5.3

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy zksolc || rpm -q zksolc || zksolc --version

2. UPGRADE to 1.5.3 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade zksolc

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade zksolc

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2024-45056?

zksolc: upgrade to 1.5.3. Exact commands for each OS are on this page.

Is CVE-2024-45056 being exploited?

CVE-2024-45056 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2024-45056 affect?

CVE-2024-45056 affects zksolc. Severity is medium (CVSS 5.9). zksolc is a Solidity compiler for ZKsync. All LLVM versions since 2015 fold `(xor (shl 1, x), -1)` to `(rotl ~1, x)` if run with optimizations enabled. Here `~1` is generated as an unsigned 64 bits number (`2^64-1`). This number is zero-ext

How urgent is CVE-2024-45056?

Priority 34/100. Remotely exploitable, no login, no user action

References

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