CVE-2026-1229: Incorrect calculation in CIRCL secp384r1 CombinedMult

Published Feb 24, 2026
·
Updated

The CombinedMult function in the CIRCL ecc/p384 package (secp384r1 curve) produces an incorrect value for specific inputs. The issue is fixed by using complete addition formulas. ECDH and ECDSA signing relying on this curve are not affected.

The bug was fixed in v1.6.3 https://github.com/cloudflare/circl/releases/tag/v1.6.3 .

Other sources

The CombinedMult function in the CIRCL ecc/p384 package (secp384r1 curve) produces an incorrect value for specific inputs. The issue is fixed by using complete addition formulas. ECDH and ECDSA signing relying on this curve are not affected.

The bug was fixed in v1.6.3.

GitHub

Affected Software

3 affected componentsFixes available
github/cloudflare/circl<1.6.3
go/github.com/cloudflare/circl<1.6.3
1.6.3
Cloudflare Circl Go<1.6.3

Event History

Feb 24, 2026
CVE Published
via MITRE·07:58 AM
Data Sourced
via MITRE·07:58 AM
DescriptionWeakness
Data Sourced
via NVD·08:16 AM
DescriptionSeverityWeakness
Data Sourced
via NVD·08:16 AM
Affected Software
Feb 25, 2026
Advisory Published
via GitHub·07:17 PM
Data Sourced
via GitHub·07:17 PM
DescriptionWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-1229?

The severity of CVE-2026-1229 is currently classified as medium due to its impact on the CombinedMult function in the CIRCL secp384r1 implementation.

2

How do I fix CVE-2026-1229?

Fix CVE-2026-1229 by updating the CIRCL library to version 1.6.3 or later, where the issue with the CombinedMult function has been addressed.

3

Which software is affected by CVE-2026-1229?

CVE-2026-1229 affects the CIRCL library, specifically versions 1.6.2 and below of the secp384r1 implementation.

4

Does CVE-2026-1229 affect ECDH and ECDSA signing?

No, CVE-2026-1229 does not affect ECDH and ECDSA signing as those operations are not reliant on the flawed CombinedMult function.

5

What does CVE-2026-1229 involve?

CVE-2026-1229 involves an incorrect calculation in the CombinedMult function of the CIRCL ecc/p384 package on the secp384r1 curve, which can produce incorrect values for specific inputs.

Contact

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