libp2p up to 15.0.23 Gossipsub message/decodeRpc.ts infinite loop

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.1$0-$5k0.00+

Summaryinfo

A vulnerability categorized as problematic has been discovered in libp2p. This vulnerability affects unknown code of the file message/decodeRpc.ts of the component Gossipsub. The manipulation results in infinite loop. This vulnerability was named CVE-2026-49866. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability classified as problematic has been found in libp2p. Affected is an unknown functionality of the file message/decodeRpc.ts of the component Gossipsub. The manipulation with an unknown input leads to a infinite loop vulnerability. CWE is classifying the issue as CWE-835. The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. This is going to have an impact on availability. CVE summarizes:

libp2p is a JavaScript Implementation of libp2p networking stack. Prior to 16.0.0, @libp2p/gossipsub defaultDecodeRpcLimits set maxIhaveMessageIDs and maxIwantMessageIDs to Infinity, allowing oversized IHAVE and IWANT control message arrays in message/decodeRpc.ts and gossipsub.ts to synchronously iterate roughly 180,000 message IDs per 4 MB frame and block the Node.js event loop. This issue is fixed in version 16.0.0.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-49866 since 06/02/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1499.

Upgrading to version 16.0.0 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.1

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Infinite loop
CWE: CWE-835 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Upgrade: libp2p 16.0.0

Timelineinfo

06/02/2026 CVE reserved
07/08/2026 +36 days Advisory disclosed
07/08/2026 +0 days VulDB entry created
07/08/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-49866 (🔒)
GCVE (CVE): GCVE-0-2026-49866
GCVE (VulDB): GCVE-100-377028

Entryinfo

Created: 07/08/2026 23:48
Changes: 07/08/2026 23:48 (53)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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