CVE-2022-41724: Panic on large handshake records in crypto/tls
Summary
CVE-2022-41724: Panic on large handshake records in crypto/tls. Affects stdlib across 2 version ranges.
< 1.19.6
>= 1.20.0-0, < 1.20.1
Fixed in 1.19.6 or 1.20.1, depending on the release line you run. How to fix ↓
Also tracked for
- golang · Bitnami
- golang-1.15 · Debian:11
The same CVE-2022-41724 is tracked separately for each ecosystem and vendor. Its fix information is the same; the package and affected versions differ.
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Background
The crypto/tls package in Go provides a secure transport layer for network connections using the Transport Layer Security (TLS) protocol. It is a part of the standard library in Go and is widely used for implementing secure communication in Go applications. However, a vulnerability has been discovered in the package that can lead to panics when processing large TLS handshake records. This vulnerability affects all TLS 1.3 clients, TLS 1.2 clients with session resumption enabled, and TLS 1.3 servers requesting client certificates.
Vulnerability Detail
The vulnerability arises when clients or servers send large TLS handshake records, causing the receiving party to panic while constructing responses. This can be triggered by both clients and servers, leading to potential denial-of-service (DoS) scenarios. Clients using TLS 1.3 or TLS 1.2 with session resumption enabled are affected, as well as TLS 1.3 servers requesting client certificates. The panic occurs during the construction of responses, which can disrupt the normal functioning of the affected application.
How To Fix
Latest published version: go1.25.5 as of 22 Oct 2026
go get stdlib@vgo1.25.5Upgrading to it may include breaking changes; the versions below are the minimum fixed release for this vulnerability.
If you can't move to the latest
The minimum fixed version depends on the release line you run.
-
< 1.19.61.19.6go get stdlib@v1.19.6 -
>= 1.20.0-0, < 1.20.11.20.1go get stdlib@v1.20.1
Tip — Not sure which release line you're on? Vulert can find the fix for the version you are using. Scan free →
Workaround
If updating the Go standard library is not immediately feasible, a possible workaround is to limit the size of the TLS handshake records. This can be achieved by configuring the application to reject or truncate excessively large handshake records. However, this workaround may impact the compatibility and functionality of the application, so updating to the fixed versions of the standard library is the recommended approach.
Conclusion
The panic on large handshake records vulnerability in the crypto/tls package can lead to denial-of-service scenarios and disrupt the normal functioning of affected applications. It is crucial to update the Go standard library to the fixed versions to mitigate this vulnerability. Regularly updating the Go installation and using tools like Vulert can help ensure the security of Go applications. For further support on vulnerability remediation, you can reach out to DevNack.com.
See every vulnerability recorded for stdlib →
FAQ
This vulnerability affects Go versions prior to 1.19.6 for TLS 1.2 clients and prior to 1.20.1 for TLS 1.3 clients and servers.
The vulnerability can lead to panics in the crypto/tls package, causing potential denial-of-service (DoS) scenarios and disrupting the normal functioning of affected applications.
Yes, all TLS 1.3 clients are affected by this vulnerability. It is recommended to update to the fixed version of the Go standard library.
A possible workaround is to limit the size of TLS handshake records, but this may impact compatibility and functionality. Updating to the fixed version of the Go standard library is the recommended approach.
You can use Vulert's playground at Vulert Scanner to check if your application is affected by this vulnerability. Vulert monitors and alerts in real-time for open-source vulnerabilities without requiring access to the code or installation.
References
Related vulnerabilities
Recent vulnerabilities recorded for stdlib.
