RHSA-2026:34359 - Security Advisory

Topic

An update for opentelemetry-collector is now available for Red Hat Enterprise Linux 9.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

Collector with the supported components for a Red Hat build of OpenTelemetry

Security Fix(es):

• github.com/prometheus/prometheus: Prometheus: Denial of Service via uncontrolled memory allocation in remote read endpoint (CVE-2026-42154)
• github.com/prometheus/prometheus: Prometheus: Information disclosure of Azure OAuth client secret via config API (CVE-2026-42151)
• net: golang: Go net package: Denial of Service via long CNAME response in LookupCNAME (CVE-2026-33811)
• golang.org/x/net/idna: golang: golang.org/x/net/idna: Privilege escalation via incorrect Punycode label processing (CVE-2026-39821)
• golang.org/x/net/html: golang.org/x/net/html: Arbitrary code execution via Cross-Site Scripting (CVE-2026-25681)
• crypto/x509: golang: golang crypto/x509: Denial of Service via excessive processing of DNS SAN entries (CVE-2026-27145)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux for x86_64 9 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 9.8 x86_64
• Red Hat Enterprise Linux for IBM z Systems 9 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 9.8 s390x
• Red Hat Enterprise Linux for Power, little endian 9 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 9.8 ppc64le
• Red Hat Enterprise Linux for ARM 64 9 aarch64
• Red Hat Enterprise Linux for ARM 64 - Extended Update Support 9.8 aarch64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.8 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.8 x86_64
• Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.8 aarch64
• Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.8 s390x
• Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.8 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.8 aarch64
• Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.8 ppc64le
• Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.8 s390x

Fixes

• BZ - 2466505 - CVE-2026-42154 github.com/prometheus/prometheus: Prometheus: Denial of Service via uncontrolled memory allocation in remote read endpoint
• BZ - 2466507 - CVE-2026-42151 github.com/prometheus/prometheus: Prometheus: Information disclosure of Azure OAuth client secret via config API
• BZ - 2467822 - CVE-2026-33811 net: golang: Go net package: Denial of Service via long CNAME response in LookupCNAME
• BZ - 2480756 - CVE-2026-39821 golang.org/x/net/idna: golang: golang.org/x/net/idna: Privilege escalation via incorrect Punycode label processing
• BZ - 2480761 - CVE-2026-25681 golang.org/x/net/html: golang.org/x/net/html: Arbitrary code execution via Cross-Site Scripting
• BZ - 2484207 - CVE-2026-27145 crypto/x509: golang: golang crypto/x509: Denial of Service via excessive processing of DNS SAN entries

CVEs

• CVE-2026-25681
• CVE-2026-27145
• CVE-2026-33811
• CVE-2026-39821
• CVE-2026-42151
• CVE-2026-42154

References

• https://access.redhat.com/security/updates/classification/#important