CVE-2026-57082

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Source

https://cve.org/CVERecord?id=CVE-2026-57082

Import Source

https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-57082.json

JSON Data

https://api.osv.dev/v1/vulns/CVE-2026-57082

Aliases

GHSA-g444-x2c5-94hc

Published

2026-06-30T11:05:33.709Z

Modified

2026-07-15T01:49:20.210540708Z

Severity

5.9 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N CVSS Calculator

Summary

Net::BitTorrent versions through 2.0.1 for Perl generate the MSE Diffie-Hellman private key with a non-cryptographic PRNG

Details

Net::BitTorrent versions through 2.0.1 for Perl generate the MSE Diffie-Hellman private key with a non-cryptographic PRNG.

The MSE (Message Stream Encryption) handshake derives its 160-bit Diffie-Hellman private key from Perl's rand(), a non-cryptographic drand48-class generator seeded once per process, in KeyExchange.pm. The shared secret and the RC4 keys derived from it (the SHA-1 of "keyA" or "keyB", the shared secret, and the infohash) therefore depend entirely on a predictable PRNG. The same handshake sends, in cleartext, random padding drawn from the same rand() sequence in randompad, immediately after the public key and the private-key draw.

A passive observer of the handshake recovers the PRNG state from the cleartext padding, reconstructs the private key, computes the shared secret from the peer's public key on the wire, derives the RC4 keys, and decrypts the connection, defeating the passive-observation obfuscation MSE provides.

Database specific

{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/57xxx/CVE-2026-57082.json",
    "cwe_ids": [
        "CWE-330",
        "CWE-338"
    ],
    "cna_assigner": "CPANSec"
}

References

Affected packages

Git / github.com/sanko/net-bittorrent.pm

Affected ranges

Type

GIT

Repo

https://github.com/sanko/net-bittorrent.pm

Events

Introduced

Fixed

081026437bb892cba52655364e203e16ad4dafd5

Database specific

{
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "last_affected": "2.0.1"
        },
        {
            "fixed": "2.0.1"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "DESCRIPTION"
    ]
}

Affected versions

v2.*

v2.0.0

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-57082.json"