CVE-2026-111943
UnknownSummary
The Go standard library (crypto/x509) added a denylist of known intermediate certificates no longer considered trustworthy. This defends against cases where system trust stores may not be updated without further action.
Risk Assessment
Organizations using Go may still trust intermediate certificates that should be rejected, potentially allowing impersonation of a trusted TLS server.
Recommendation
Update the Go toolchain to a version containing this denylist and ensure system trust stores are kept up to date.
Other vulnerabilities in Go crypto/x509
See all- CVE-2026-32280High
During chain building, the amount of work is not correctly limited when a large number of intermediate certificates are passed in VerifyOptions.Intermediates, which can lead to denial of service. This affects both direct users of crypto/x509 and users of crypto/tls.
- CVE-2025-61729High
Within HostnameError.Error(), there is no limit to the number of hosts printed when constructing an error string, and the string is built by repeated concatenation, leading to quadratic runtime. A certificate provided by a malicious actor can result in excessive resource consumption.
Original NVD description (English source)
On most platforms, Go uses the given system root certificates. However, in some narrower cases, the system trust stores may not be updated without further action. To defend against the narrower set of cases that may remain affected, a denylist was added in crypto/x509 to return an error when calling Verify with any of the known intermediate certificates that are no longer considered to be trustworthy.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS