Answer in brief
CVE-2023-39533 records a High severity (CVSS 7.5) vulnerability in libp2p nodes vulnerable to attack using large RSA keys. The current sources do not mark it as known exploited. The current feed maps libp2p/go-libp2p (generic), github.com/libp2p/go-libp2p (go), github.com/libp2p/go-libp2p (go), github.com/libp2p/go-libp2p (go) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps libp2p/go-libp2p (generic), github.com/libp2p/go-libp2p (go), github.com/libp2p/go-libp2p (go), github.com/libp2p/go-libp2p (go) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| libp2p/go-libp2pgeneric | < 0.27.8 || >= 0.28.0, < 0.28.2 || = 0.29.0 | Not reported |
| github.com/libp2p/go-libp2pgo | >=0 <0.27.8 | 0.27.8 |
| github.com/libp2p/go-libp2pgo | >=0.28.0 <0.28.2 | 0.28.2 |
| github.com/libp2p/go-libp2pgo | >=0.29.0 <0.29.1 | 0.29.1 |
| github.com/libp2p/go-libp2pgo | <0.27.8 | 0.27.8 |
| github.com/libp2p/go-libp2pgo | >=0.28.0,<0.28.2 | 0.28.2 |
| github.com/libp2p/go-libp2pgo | =0.29.0 | 0.29.1 |
Published upstream
Aug 8, 2023
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 1, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 7, 2026
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.
Quoted source text, attributed separately from HOL analysis.