CVE-2026-1229

CVE-2026-1229 is a critical-severity vulnerability in Cloudflare Circl with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-682.

Key facts

Description

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 .

Frequently asked questions

What is 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 affected. The bug was fixed in v1.6.3 https://github.com/cloudflare/circl/releases/tag/v1.6.3 .
How severe is CVE-2026-1229?
CVE-2026-1229 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-1229 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-1229?
CVE-2026-1229 affects Cloudflare Circl. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-1229?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-1229 have an EU (EUVD) identifier?
Yes. CVE-2026-1229 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-7384.
When was CVE-2026-1229 published?
CVE-2026-1229 was published on 2026-02-24 and last updated on 2026-06-17.

References

Affected products (1)

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