What is CVE-2026-1229?

CVE-2026-1229 is a critical-severity vulnerability in Cloudflare Circl, classified under Incorrect Calculation. CVSS score: 9.8/10. Published 2026-02-24.

How severe is CVE-2026-1229?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Cloudflare Circl

CVE-2026-1229

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 affecte…

EPSS: 0.004 (31.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Cloudflare Circl — versions CIRCL up to version 1.6.2

Weakness classification (CWE)

CWE-682 — Incorrect Calculation

References

cna@cloudflare.com (Product)

Frequently asked questions

What is CVE-2026-1229?: CVE-2026-1229 is a critical-severity vulnerability in Cloudflare Circl, classified under Incorrect Calculation. CVSS score: 9.8/10. Published 2026-02-24.
How severe is CVE-2026-1229?: Critical severity. CVSS v3 base score is 9.8 out of 10.