RHSA-2026:37276HighCVSS 8.8

Red Hat Security Advisory: RHTAS 1.4.2 - CLI Stack Release

Published
July 9, 2026
Last Modified
July 27, 2026

🔗 CVE IDs covered (14)

CVE-2026-42151 →CVE-2026-42508 →CVE-2026-46595 →CVE-2026-27145 →CVE-2026-39820 →CVE-2026-39821 →CVE-2026-39830 →CVE-2026-39833 →CVE-2026-42499 →CVE-2026-33811 →CVE-2026-39828 →CVE-2026-39829 →CVE-2026-39832 →CVE-2026-39835 →

📋 Description

CVE-2026-27145 — crypto/x509: golang: golang crypto/x509: Denial of Service via excessive processing of DNS SAN entries CVE-2026-33811 — net: golang: Go net package: Denial of Service via long CNAME response in LookupCNAME CVE-2026-39820 — net/mail: golang: Go net/mail: Denial of Service via crafted email inputs CVE-2026-39821 — golang.org/x/net/idna: golang: net/http: golang.org/x/net/idna: Privilege escalation via incorrect Punycode label processing CVE-2026-39828 — golang.org/x/crypto/ssh: golang.org/x/crypto/ssh: Unauthorized command execution via discarded SSH permissions CVE-2026-39829 — golang.org/x/crypto/ssh: golang.org/x/crypto/ssh: Denial of Service via crafted public key with excessive parameters CVE-2026-39830 — golang.org/x/crypto/ssh: golang.org/x/crypto/ssh: Denial of Service via resource leak from unsolicited SSH responses CVE-2026-39832 — golang.org/x/crypto/ssh/agent: golang.org/x/crypto/ssh/agent: Security bypass due to improper handling of key restrictions CVE-2026-39833 — golang.org/x/crypto/ssh/agent: golang.org/x/crypto/ssh/agent: Security bypass due to unenforced key confirmation CVE-2026-39835 — golang.org/x/crypto/ssh: golang: golang.org/x/crypto/ssh: Denial of Service via crafted SSH certificate CVE-2026-42151 — github.com/prometheus/prometheus: Prometheus: Information disclosure of Azure OAuth client secret via config API CVE-2026-42499 — net/mail: golang: net/mail: Denial of Service via pathological email address parsing CVE-2026-42508 — golang.org/x/crypto/ssh/knownhosts: golang: golang.org/x/crypto/ssh/knownhosts: Revocation bypass via unchecked SignatureKey CVE-2026-46595 — golang.org/x/crypto/ssh: golang.org/x/crypto/ssh: Authorization bypass due to skipped source-address validation

🎯 Affected products51

  • Red Hat Trusted Artifact Signer 1.4
  • conforma-cli-stack-v1-4@amd64 as a component of Red Hat Trusted Artifact Signer 1.4
  • conforma-cli-stack-v1-4@amd64_darwin as a component of Red Hat Trusted Artifact Signer 1.4
  • conforma-cli-stack-v1-4@amd64_windows as a component of Red Hat Trusted Artifact Signer 1.4
  • conforma-cli-stack-v1-4@arm64 as a component of Red Hat Trusted Artifact Signer 1.4
  • conforma-cli-stack-v1-4@arm64_darwin as a component of Red Hat Trusted Artifact Signer 1.4
  • conforma-cli-stack-v1-4@ppc64le as a component of Red Hat Trusted Artifact Signer 1.4
  • conforma-cli-stack-v1-4@s390x as a component of Red Hat Trusted Artifact Signer 1.4
  • cosign-cli-stack-v1-4@amd64 as a component of Red Hat Trusted Artifact Signer 1.4
  • cosign-cli-stack-v1-4@amd64_darwin as a component of Red Hat Trusted Artifact Signer 1.4
  • cosign-cli-stack-v1-4@amd64_windows as a component of Red Hat Trusted Artifact Signer 1.4
  • cosign-cli-stack-v1-4@arm64 as a component of Red Hat Trusted Artifact Signer 1.4
  • cosign-cli-stack-v1-4@arm64_darwin as a component of Red Hat Trusted Artifact Signer 1.4
  • cosign-cli-stack-v1-4@ppc64le as a component of Red Hat Trusted Artifact Signer 1.4
  • cosign-cli-stack-v1-4@s390x as a component of Red Hat Trusted Artifact Signer 1.4
  • fetch-tsa-certs-cli-stack-v1-4@amd64 as a component of Red Hat Trusted Artifact Signer 1.4
  • fetch-tsa-certs-cli-stack-v1-4@amd64_darwin as a component of Red Hat Trusted Artifact Signer 1.4
  • fetch-tsa-certs-cli-stack-v1-4@amd64_windows as a component of Red Hat Trusted Artifact Signer 1.4
  • fetch-tsa-certs-cli-stack-v1-4@arm64 as a component of Red Hat Trusted Artifact Signer 1.4
  • fetch-tsa-certs-cli-stack-v1-4@arm64_darwin as a component of Red Hat Trusted Artifact Signer 1.4
  • fetch-tsa-certs-cli-stack-v1-4@ppc64le as a component of Red Hat Trusted Artifact Signer 1.4
  • fetch-tsa-certs-cli-stack-v1-4@s390x as a component of Red Hat Trusted Artifact Signer 1.4
  • gitsign-cli-stack-v1-4@amd64 as a component of Red Hat Trusted Artifact Signer 1.4
  • gitsign-cli-stack-v1-4@amd64_darwin as a component of Red Hat Trusted Artifact Signer 1.4
  • gitsign-cli-stack-v1-4@amd64_windows as a component of Red Hat Trusted Artifact Signer 1.4
  • gitsign-cli-stack-v1-4@arm64 as a component of Red Hat Trusted Artifact Signer 1.4
  • gitsign-cli-stack-v1-4@arm64_darwin as a component of Red Hat Trusted Artifact Signer 1.4
  • gitsign-cli-stack-v1-4@ppc64le as a component of Red Hat Trusted Artifact Signer 1.4
  • gitsign-cli-stack-v1-4@s390x as a component of Red Hat Trusted Artifact Signer 1.4
  • model-transparency-cli-stack-v1-4@amd64 as a component of Red Hat Trusted Artifact Signer 1.4
  • +21 more not shown

✅ Remediation

The RHTAS CLI Stack images contain Red Hat Trusted Artifact Signer CLI binaries. For details on using the CLI images, refer to the product documentation at https://access.redhat.com/documentation/en-us/red_hat_trusted_artifact_signer/1.4 You can find the release notes for this version of Red Hat Trusted Artifact Signer at https://access.redhat.com/documentation/en-us/red_hat_trusted_artifact_signer/1.4/html-single/release_notes/index Workaround: A flaw was found in the Go standard library crypto/x509 package. When verifying a TLS certificate hostname, VerifyHostname processed each DNS Subject Alternative Name (SAN) entry in a loop and repeatedly split the candidate hostname on "." characters. For certificates with a very large DNS SAN list, CPU use could grow quadratically with the number of SAN entries and hostname labels. Because hostname verification runs before the certificate chain is built, this overhead can occur even when the certificate is not trusted. Red Hat rates this issue as Important. It affects Red Hat products that include the Go standard library crypto/x509 code from an affected Go toolchain version (before Go 1.25.11, or from Go 1.26.0 through Go 1.26.3). Applications and container images built with a fixed Go release (1.25.11 or later, or 1.26.4 or later) are not affected. Community distributions such as Fedora are also affected. Upstream fix: Go 1.25.11 and Go 1.26.4 (GO-2026-5037). Workaround: To mitigate this issue, applications can be configured to use the pure Go DNS resolver instead of the `cgo` DNS resolver. This can be achieved by setting the `GODEBUG` environment variable to `netdns=go`. For example, to run a Go application with this mitigation: `GODEBUG=netdns=go /path/to/your/go/application`. This change may require restarting affected applications or services to take effect. Users should verify that this change does not negatively impact DNS resolution for their specific application environment. Workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. Workaround: Upgrade to a fixed golang.org/x/net release that includes the idna correction, via updated golang or dependent package rebuilds. Workaround: To mitigate this denial of service vulnerability, restrict network access to any service that utilizes the `golang.org/x/crypto/ssh` library and is exposed to untrusted networks. Implement firewall rules to allow connections only from trusted hosts or networks. This action limits the ability of malicious peers to send unsolicited global request responses. A restart of the affected service may be necessary for the new network rules to be applied effectively. Workaround: Update affected Go applications to use golang.org/x/crypto version 0.52.0 or later, which rejects unsupported ConfirmBeforeUse keys instead of silently ignoring the constraint. As a workaround, do not add keys with ConfirmBeforeUse to the in-memory keyring from golang.org/x/crypto/ssh/agent, or use an SSH agent implementation that correctly enforces confirm-before-use. Workaround: Upgrade to a fixed golang.org/x/crypto/ssh release via updated golang or package rebuilds. Ensure SSH servers use supported public-key callback configurations with source-address validation as intended.

🔗 References (19)