CVE-2026-86040: js-libp2p · Uncontrolled Resource Consumption
Affects js-libp2pSource CVE Database V5
Not known to be exploited · CVSS 7.5 High : upgrade to 11.0.26 soon.
Data as of 1 Nov 2026, 11:03 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 51% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 11.0.26
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 17 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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 1 Nov 2026.
What to do
Upgrade js-libp2p and floodsub to 11.0.26.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| libp2pjs-libp2p | Affected
| Fixed in
|
| @libp2pfloodsub | Affected
| Fixed in
|
AI-suggested
Upgrade js-libp2p to version 11.0.26 or later, where this vulnerability is fixed. No other mitigations are indicated by the vendor advisory.
Description
libp2p is a JavaScript implementation of the libp2p networking stack. Prior to 11.0.26, @libp2p/floodsub accepts unauthenticated RPC frames on /floodsub/1.0.0 through PeerStreams.attachInboundStream in packages/floodsub/src/peer-streams.ts without protobuf element limits, then processRpc and processRpcSubOpt in packages/floodsub/src/floodsub.ts synchronously process the subscriptions array without a per-frame cap. A single bounded-size frame can decode into millions of empty subscription entries that block the event loop, while hundreds of thousands of unique-topic SUBSCRIBE entries allocate PeerSet objects in this.topics that are not removed after peer removal or stop. Empty entries cause CPU exhaustion but do not grow this.topics; persistent memory growth requires unique topics. The subscription path bypasses message signature validation and the message-only processing queue, allowing a remote peer to cause sustained CPU denial of service, memory exhaustion, out-of-memory termination, and node unavailability. The issue is fixed in version 11.0.26.
References
- github.com/libp2p/js-libp2p/security/advisories/GHSA-cvfg-hcf3-ggwv (opens in a new tab)
- github.com/libp2p/js-libp2p/pull/3568 (opens in a new tab)
- github.com/libp2p/js-libp2p/commit/fb9e8a76e9ac75924928fae4ce11d00f68320a83 (opens in a new tab)
- github.com/libp2p/js-libp2p/releases/tag/floodsub-v11.0.26 (opens in a new tab)