CVE-2023-39533

libp2p nodes vulnerable to attack using large RSA keys

HIGH
7.5
CVSS Score
Published: August 8, 2023 at 06:50 PM UTC
Updated: September 1, 2026 at 10:17 PM UTC
1 product affected across 1 vendorGo LIBP2P

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Severity
HIGH7.5
Exploit prediction
EPSS 2%
SSVC
PoC

Description

go-libp2p is the Go implementation of the libp2p Networking Stack. Prior to versions 0.27.8, 0.28.2, and 0.29.1 malicious peer can use large RSA keys to run a resource exhaustion attack & force a node to spend time doing signature verification of the large key. This vulnerability is present in the core/crypto module of go-libp2p and can occur during the Noise handshake and the libp2p x509 extension verification step. To prevent this attack, go-libp2p versions 0.27.8, 0.28.2, and 0.29.1 restrict RSA keys to <= 8192 bits. To protect one's application, it is necessary to update to these patch releases and to use the updated Go compiler in 1.20.7 or 1.19.12. There are no known workarounds for this issue.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.27.8v < 0.28.20.28.0 ≤ v < 0.28.20.29.0= 0.29.0
Affected range stops below 0.27.8, so it looks safe — our inference, not a vendor statement
Affected range stops below 0.28.2, so it looks safe — our inference, not a vendor statement

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-770

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