CVE-2026-1229 Incorrect calculation in CIRCL secp384r1 CombinedMult
Incorrect calculation in CIRCL secp384r1 CombinedMult produces wrong values for specific inputs, though ECDH and ECDSA remain unaffected.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-1229?
CVE-2026-1229 is a low-severity vulnerability in Cloudflare CIRCL, published on 24 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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 .
Weakness: CWE-682
Which versions are affected by CVE-2026-1229?
3 open source packages ship an affected version, including github.com/cloudflare/circl. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/cloudflare/circl Go | All versions | 1.6.3 |
github.com/cloudflare/circl Go | All versions | 1.6.3 |
github.com/cloudflare/circl Go | All versions | 1.6.3 |
Linux distribution packages (3)
enc openSUSE:Leap 16.0 | All versions | 1.1.5-bp160.1.1 |
amazon-ssm-agent openSUSE:Tumbleweed | All versions | 3.3.4121.0-1.1 |
enc openSUSE:Tumbleweed | All versions | 1.1.5-2.1 |
Products include Cloudflare Circl.
How do I fix CVE-2026-1229?
Upgrade github.com/cloudflare/circl to 1.6.3 or later.
Is CVE-2026-1229 being exploited?
There is no known exploitation of CVE-2026-1229 in the wild and no public exploit code.
Other vulnerabilities in Cloudflare CIRCL
Sources
Also known as CLEANSTART-2026-LG65775, CLEANSTART-2026-PC68817, CLEANSTART-2026-PN12156, CLEANSTART-2026-VP63638, GHSA-q9hv-hpm4-hj6x, GO-2026-4550 and 131 more.