How severe is CVE-2023-44378?

CVE-2023-44378 has a CVSS score of 7.1/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-44378?

CVE-2023-44378 affects the following packages: github.com/consensys/gnark (Go). Ecosystems affected: Go.

How do I fix CVE-2023-44378?

Update github.com/consensys/gnark to 0.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-44378 is resolved across your whole dependency graph.

How do I detect CVE-2023-44378 in my Go dependencies?

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

How do I mitigate CVE-2023-44378 if there is no patch (or I can't update yet)?

Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

Is CVE-2023-44378 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-44378 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 CVE-2023-44378?

CVE-2023-44378 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 14th 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 CVE-2023-44378?

CVE-2023-44378 is classified as CWE-191 (CWE-191), CWE-697 (CWE-697). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2023-44378 published, and has it been updated?

CVE-2023-44378 was published on October 9, 2023 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹

🐹 Go

Not in CISA KEV

HIGH severity

CVE-2023-44378 — gnark

HIGHFix: Consensys/gnark@59a4087

CVE-2023-44378 is a high-severity (CVSS 7.1) CWE-191 vulnerability in github.com/consensys/gnark. A fix is available for github.com/consensys/gnark — see the affected versions and patch details below.

gnark vulnerable to unsoundness in variable comparison/non-unique binary decomposition

Also known asGHSA-498w-5j49-vqjgGO-2023-2098

Published

Oct 9, 2023

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2023-44378.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs14th percentile — riskier than 14% of all scored CVEsHighest risk

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

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🐹github.com/consensys/gnark

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

Description

Impact

For some in-circuit values, it is possible to construct two valid decomposition to bits. In addition to the canonical decomposition of a, for small values there exists a second decomposition for a+r (where r is the modulus the values are being reduced by). The second decomposition was possible due to overflowing the field where the values are defined.

Internally, the comparison methods frontend.API.Cmp and frontend.API.IsLess used binary decomposition and checked the bitwise differences. This allows a malicious prover to construct a valid proof for a statement a < b even if a > b.

The issue impacts all users using API.Cmp or API.IsLess methods. Additionally, it impacts the users using bits.ToBinary or API.ToBinary methods if full-width decomposition is requested (the default behaviour if no options are given).

The issues does not impact comparison methods in field emulation (package std/math/emulated) and dedicated comparison package (std/math/cmp).

Patches

Fix has been implemented in pull request #835 and merged in commit 59a4087261a6c73f13e80d695c17b398c3d0934f to master branch. The release v0.9.0 and onwards include the fix.

The fix added additional comparison of the decomposed bit-vector to the modulus of the in-circuit values.

Workarounds

Upgrading to version v0.9.0 should fix the issue without needing to change the calls to value comparison methods.

Alternatively, users can use the std/math/cmp gadget, which additionally allows to bound the number of bits being compared, making the comparisons more efficient if the bound on the absolute difference of the values is known.

References

Acknowledgement

The vulnerability was reported by Marcin Kostrzewa @ Reilabs.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/consensys/gnark`	all versions	0.9.0`go get github.com/consensys/gnark@v0.9.0`

Affected Products

1 product · 1 configurations

Application

gnarkconsensys

< 0.9.0

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/consensys/gnark, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/consensys/gnark to 0.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-44378 is resolved across your whole dependency graph.
Workarounds
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

Frequently Asked Questions

### Impact For some in-circuit values, it is possible to construct two valid decomposition to bits. In addition to the canonical decomposition of `a`, for small values there exists a second decomposition for `a+r` (where `r` is the modulus the values are being reduced by). The second decomposition was possible due to overflowing the field where the values are defined. Internally, the comparison methods `frontend.API.Cmp` and `frontend.API.IsLess` used binary decomposition and checked the bitwise differences. This allows a malicious prover to construct a valid proof for a statement `a < b` ev