GHSA-ppp5-5v6c-4jwp: Forge has signature forgery in RSA-PKCS due to ASN.1 extra field

The Forge library has a vulnerability in its RSA signature verification that allows attackers to forge signatures on keys with low public exponents (like e=3). The flaw occurs because Forge's ASN.1 parser (a format for encoding data structures) doesn't strictly validate the signature structure — it allows extra garbage bytes inside the ASN.1 container and doesn't enforce the required minimum 8 bytes of padding, enabling attackers to construct fake signatures that pass Forge's checks but would be rejected by other cryptographic libraries like OpenSSL.