CVE-2026-4258

7.7 highEPSS 0.3%

Versions of the package sjcl before 1.0.9 are vulnerable to Improper Verification of Cryptographic Signature due to missing point-on-curve validation in sjcl.ecc.basicKey.publicKey(). An attacker can recover a victim's ECDH private key by sending crafted off-curve public keys and observing ECDH outputs. The dhJavaEc() function directly returns the raw x-coordinate of the scalar multiplication result (no hashing), providing a plaintext oracle without requiring any decryption feedback.

Severity

CVSS 4.0

7.7 high

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P

CVSS 3.1

7.5 high

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS: 0.3% chance of exploitation in the next 30 days; higher than 17% of CVEs (scores of 2026-10-31)
CWEs: CWE-347, CWE-325
Published: 2026-03-17
Modified: 2026-07-28
Record from: the NVD, synced 2026-10-19

Affected

bitwiseshiftleft:stanford_javascript_crypto_library

Packages (OSV)

Advisory	Ecosystem	Package	Affected	Fixed in
GHSA-2w8x-224x-785m	npm	sjcl	<1.0.9	1.0.9

References

Check your stack JSON