CVE-2023-39533
libp2p nodes vulnerable to attack using large RSA keys
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
7.5
libp2p nodes vulnerable to attack using large RSA keys
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.
- Record
CVE-2023-39533- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
EUVDEUVD-2023-2242
7.5
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.
- Record
EUVD-2023-2242- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-876p-8259-xjgg
7.5
libp2p nodes vulnerable to attack using large RSA keys
Impact
A 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 now restricts RSA keys to <= 8192 bits.
Patches
Users should upgrade their go-libp2p versions to >=v0.27.8, >= v0.28.2, or >=v0.29.1 To protect your application, it's necessary to update to these patch releases AND to use the updated Go compiler (1.20.7 or 1.19.12, respectively)
Workarounds
There are no known workarounds
References
The Golang crypto/tls package also had this vulnerability ("verifying certificate chains containing large RSA keys is slow” https://github.com/golang/go/issues/61460) Fix in golang/go crypto/tls: https://github.com/golang/go/commit/2350afd2e8ab054390e284c95d5b089c142db017 Fix in quic-go https://github.com/quic-go/quic-go/pull/4012
- Record
GHSA-876p-8259-xjgg- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
NVD
7.5
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.
- Record
CVE-2023-39533- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
OSVAZL-27872
7.5
CVE-2023-39533 affecting package golang for versions less than 1.19.12-1
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.
- Record
AZL-27872- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVAZL-27875
7.5
CVE-2023-39533 affecting package msft-golang for versions less than 1.19.12-1
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.
- Record
AZL-27875- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Show 8 moreShow less
OSVAZL-37359
7.5
CVE-2023-39533 affecting package golang for versions less than 1.21.6-1
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.
- Record
AZL-37359- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVAZL-37422
7.5
CVE-2023-39533 affecting package golang for versions less than 1.21.6-1
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.
- Record
AZL-37422- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVAZL-52773
7.5
CVE-2023-39533 affecting package golang for versions less than 1.19.12-1
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.
- Record
AZL-52773- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVAZL-79074
7.5
CVE-2023-39533 affecting package golang 1.25.7-1
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.
- Record
AZL-79074- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVAZL-98640
7.5
CVE-2023-39533 affecting package golang 1.27.1-1
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.
- Record
AZL-98640- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSV
7.5
libp2p nodes vulnerable to attack using large RSA keys
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.
- Record
CVE-2023-39533- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
OSVGHSA-876p-8259-xjgg
7.5
libp2p nodes vulnerable to attack using large RSA keys
Impact
A 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 now restricts RSA keys to <= 8192 bits.
Patches
Users should upgrade their go-libp2p versions to >=v0.27.8, >= v0.28.2, or >=v0.29.1 To protect your application, it's necessary to update to these patch releases AND to use the updated Go compiler (1.20.7 or 1.19.12, respectively)
Workarounds
There are no known workarounds
References
The Golang crypto/tls package also had this vulnerability ("verifying certificate chains containing large RSA keys is slow” https://github.com/golang/go/issues/61460) Fix in golang/go crypto/tls: https://github.com/golang/go/commit/2350afd2e8ab054390e284c95d5b089c142db017 Fix in quic-go https://github.com/quic-go/quic-go/pull/4012
- Record
GHSA-876p-8259-xjgg- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
OSVGO-2023-2000 No score
Large RSA keys can cause high resource usage in github.com/libp2p/go-libp2p
Large RSA keys can lead to resource exhaustion attacks.
With fix, the size of RSA keys transmitted during handshakes is restricted to <= 8192 bits.
- Record
GO-2023-2000- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
github.com/libp2p/go-libp2pGo |
before 0.27.8 | 0.27.8 |
github.com/libp2p/go-libp2pGo |
0.28.0 up to 0.28.2 | 0.28.2 |
github.com/libp2p/go-libp2pGo |
0.29.0 to 0.29.0 | 0.29.1 |
golangAzure Linux:2 |
1.19.0 up to 1.19.12-1 | 1.19.12-1 |
msft-golangAzure Linux:2 |
before 1.19.12-1 | 1.19.12-1 |
golangAzure Linux:2 |
before 1.21.6-1 | 1.21.6-1 |
golangAzure Linux:2 |
1.18.0 up to 1.21.6-1 | 1.21.6-1 |
golangAzure Linux:3 |
before 1.19.12-1 | 1.19.12-1 |
golangAzure Linux:3 |
through 1.25.7-1 | None known |
golangAzure Linux:3 |
1.27.0 to 1.27.1-1 | None known |
github.com/libp2p/go-libp2pGo |
0.29.0 up to 0.29.1 | 0.29.1 |
github.com/libp2p/go-libp2pGo |
before 0.27.8, 0.28.0 up to 0.28.2, 0.29.0 up to 0.29.1 | 0.27.80.28.20.29.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-39533 is a high vulnerability (CVSS 7.5) in Libp2p Go-libp2p, published August 8, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.51%, the 74th percentile. Fixed in github.com/libp2p/go-libp2p 0.27.8.
References
github.com/libp2p/go-libp2p/security/advisories/GHSA-876p-8259-xjgg
github.com/golang/go/issues/61460
github.com/libp2p/go-libp2p/pull/2454
github.com/quic-go/quic-go/pull/4012
github.com/golang/go/commit/2350afd2e8ab054390e284c95d5b089c142db017
github.com/libp2p/go-libp2p/commit/0cce607219f3710addc7e18672cffd1f1d912fbb
Show 8 moreShow less
github.com/libp2p/go-libp2p/commit/445be526aea4ee0b1fa5388aa65d32b2816d3a00
github.com/libp2p/go-libp2p/commit/e30fcf7dfd4715ed89a5e68d7a4f774d3b9aa92d
nrdax.com/techniques/NRDAX-T0205-pre-handshake-crypto-cpu-burn
nvd.nist.gov/vuln/detail/CVE-2023-39533
go.dev/issue/61460
github.com/advisories/GHSA-876p-8259-xjgg
github.com/CVEProject/cvelistV5/tree/main/cves/2023/39xxx/CVE-2023-39533.json
github.com/libp2p/go-libp2p