RHSA-2026:53415HighCVSS 8.6

Red Hat Security Advisory: opentelemetry-collector security update

Published
August 11, 2026
Last Modified
August 20, 2026

🔗 CVE IDs covered (8)

CVE-2026-33811 →CVE-2026-39821 →CVE-2026-42151 →CVE-2026-42154 →CVE-2026-43870 →CVE-2026-25681 →CVE-2026-27136 →CVE-2026-27145 →

📋 Description

CVE-2026-25681 — golang.org/x/net/html: golang.org/x/net/html: Arbitrary code execution via Cross-Site Scripting CVE-2026-27136 — golang.org/x/net/html: golang: golang.org/x/net/html: Cross-Site Scripting via HTML parsing bypass 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-2026-39821 — golang.org/x/net/idna: golang: net/http: golang.org/x/net/idna: Privilege escalation via incorrect Punycode label processing CVE-2026-42151 — github.com/prometheus/prometheus: Prometheus: Information disclosure of Azure OAuth client secret via config API CVE-2026-42154 — github.com/prometheus/prometheus: Prometheus: Denial of Service via uncontrolled memory allocation in remote read endpoint CVE-2026-43870 — apache-thrift: Apache Thrift: Denial of Service via multiple vulnerabilities

🎯 Affected products6

  • Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • opentelemetry-collector-0:0.152.1-1.el9_6.aarch64 as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • opentelemetry-collector-0:0.152.1-1.el9_6.ppc64le as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • opentelemetry-collector-0:0.152.1-1.el9_6.s390x as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • opentelemetry-collector-0:0.152.1-1.el9_6.src as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • opentelemetry-collector-0:0.152.1-1.el9_6.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS (v.9.6)

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Workaround: To mitigate this flaw, applications processing untrusted HTML input must implement strict input sanitization and ensure all output is properly encoded before rendering. Deploying a comprehensive Content Security Policy (CSP) can restrict script execution, further reducing the attack surface. Administrators should review application configurations to ensure adequate protection against XSS. 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: 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: 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 issue, restrict network access to the Prometheus remote read endpoint (/api/v1/read). Configure firewall rules or network policies to permit connections only from trusted internal networks or authorized clients. This action reduces the attack surface by limiting exposure to unauthenticated remote attackers. A service restart or reload may be required for the changes to take effect.

🔗 References (11)