high7.5
CVE-2026-4258
sjcl is missing point-on-curve validation in sjcl.ecc.basicKey.publicKey
Impact
All versions of the package sjcl 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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | sjcl | <= 1.0.8 | 1.0.9 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Bitwiseshiftleft | Stanford Javascript Crypto Library | through 1.0.8 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://gist.github.com/Kr0emer/2560f98edb10b0b34f2438cd63913c47
- https://github.com/bitwiseshiftleft/sjcl/blob/master/core/ecc.js%23L454-L461
- https://github.com/bitwiseshiftleft/sjcl/commit/ee307459972442a17beebc29dc331fffd8aff796
- https://security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-15751243
- https://security.snyk.io/vuln/SNYK-JS-SJCL-15369617
- https://github.com/advisories/GHSA-2w8x-224x-785m
- https://nvd.nist.gov/vuln/detail/CVE-2026-4258
- https://github.com/bitwiseshiftleft/sjcl/blob/master/core/ecc.js#L454-L461