TI-2023-01625 Aliases CVE-2023-1732 GHSA-2q89-485c-9j2x

Improper random reading in CIRCL

LOW 36CWE-20Published 2023-05-10 · Updated 2025-01-27

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: Low · High · None
Fix status: Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub.

Summary

When sampling randomness for a shared secret, the implementation of Kyber and FrodoKEM, did not check whether crypto/rand.Read() returns an error. In rare deployment cases (error thrown by the Read() function), this could lead to a predictable shared secret. The tkn20 and blindrsa components did not check whether enough randomness was returned from the user provided randomness source. Typically the user provides crypto/rand.Reader, which in the vast majority of cases will always return the right number random bytes. In the cases where it does not, or the user provides a source that does not, the blinding for blindrsa is weak and integrity of the plaintext is not ensured in tkn20.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00386 32nd percentileScored 2026-11-07

Fix Fixed CIRCL (Cloudflare): <1.3.3github.com/cloudflare/circl (Go): 1.3.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Cloudflare	CIRCL	before <1.3.3	<1.3.3	Patch available	CNA
—	github.com/cloudflare/circl (Go)	before 1.3.3	1.3.3	Patch available	GHSA-2q89-485c-9j2x

CIRCL VendorCloudflare Affected before <1.3.3 Fixed in <1.3.3 Patch available CNA
github.com/cloudflare/circl (Go) Vendor— Affected before 1.3.3 Fixed in 1.3.3 Patch available GHSA-2q89-485c-9j2x

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:cloudflare:circl::::::go::*	before 1.3.3	Vulnerable	Cloudflare

cpe:2.3:a:cloudflare:circl:*:*:*:*:*:go:*:* Versions before 1.3.3 Vulnerable ·Cloudflare

Remediation

Fix · CNA CIRCL (Cloudflare) Fixed in <1.3.3
Fix · GHSA-2q89-485c-9j2x github.com/cloudflare/circl (Go) Fixed in 1.3.3 Advisory →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product

Red Hat

Timeline

2026-10-02 Threatist record created from CVE-2023-1732
2026-10-03 Alias added: GHSA-2q89-485c-9j2x

References

Advisory 2

Other 3

TI-2026-00950 Incorrect calculation in CIRCL secp384r1 CombinedMult CVSS 4.0LOW 2.9

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences