bdecode recurses once per nested list or dictionary level with no depth cap, and each recursive call receives the remaining buffer by value while the list and dictionary branches capture the whole remainder, so every live recursion frame keeps its own copy of the shrinking buffer (O(N^2) bytes for an N-deep input). The decoder runs on every untrusted bencode source: .torrent files, BEP09 metadata fetched from peers, DHT messages, and tracker responses.
A bencoded input of roughly 150,000 nested lists (about 150 KB on the wire) drives multi-gigabyte peak memory, so one short message from any peer, or one crafted .torrent file or magnet link, terminates the client.
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| SANKO | Net::BitTorrent | unaffected |
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No data available yet.
Vendor Workaround
There is no fixed release. Cap the bencode nesting depth (libtorrent rejects beyond about 100 levels) and decode without copying the buffer remainder at each level.
Tracking
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Tue, 30 Jun 2026 15:30:00 +0000
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cvssV3_1
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Tue, 30 Jun 2026 11:45:00 +0000
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| Description | Net::BitTorrent versions through 2.0.1 for Perl allow remote memory exhaustion via deeply nested bencoded input. bdecode recurses once per nested list or dictionary level with no depth cap, and each recursive call receives the remaining buffer by value while the list and dictionary branches capture the whole remainder, so every live recursion frame keeps its own copy of the shrinking buffer (O(N^2) bytes for an N-deep input). The decoder runs on every untrusted bencode source: .torrent files, BEP09 metadata fetched from peers, DHT messages, and tracker responses. A bencoded input of roughly 150,000 nested lists (about 150 KB on the wire) drives multi-gigabyte peak memory, so one short message from any peer, or one crafted .torrent file or magnet link, terminates the client. | |
| Title | Net::BitTorrent versions through 2.0.1 for Perl allow remote memory exhaustion via deeply nested bencoded input | |
| Weaknesses | CWE-400 CWE-674 |
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| References |
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Subscriptions
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MITRE
Status: PUBLISHED
Assigner: CPANSec
Published:
Updated: 2026-06-30T15:04:17.344Z
Reserved: 2026-06-23T18:20:33.514Z
Link: CVE-2026-57081
Vulnrichment
Updated: 2026-06-30T15:04:00.752Z
NVD
No data.
Redhat
No data.
OpenCVE Enrichment
Updated: 2026-06-30T14:00:06Z