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VulnerabilityPublished Updated

CVE-2026-57082: SANKO Net::BitTorrent · PRNG

Affects SANKO Net::BitTorrentSource CVE Database V5

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Not known to be exploited · CVSS 5.9 Medium : upgrade to 2.1.0 when convenient.

Data as of 12 Nov 2026, 23:24 UTC

CVSS 3.1 base score
5.9Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.2% chance of exploitation in 30 days – higher than 14% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 2.1.0
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 30 Jun 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.

What to do

Upgrade Net::BitTorrent and Net-BitTorrent to 2.1.0.

Affected software

ProductAffectedFixed in
SANKONet::BitTorrentAffected
  • <2.1.0
Fixed in
  • 2.1.0
GitHubNet-BitTorrentpkg:github/Net-BitTorrentOther threatsAffected
  • <2.1.0
Fixed in
  • 2.1.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Users should upgrade to Net::BitTorrent version 2.1.0 or later, where this issue is resolved. Until then, avoid using affected versions (<=2.0.1) in environments where confidentiality of BitTorrent traffic is required.

Description

Net::BitTorrent versions before 2.1.0 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 _random_pad, 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.

References

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