Red Hat Security Advisory: golang-github-openprinting-ipp-usb security update
🔗 CVE IDs covered (11)
📋 Description
CVE-2026-27145 — crypto/x509: golang: golang crypto/x509: Denial of Service via excessive processing of DNS SAN entries CVE-2026-32281 — crypto/x509: golang: Go crypto/x509: Denial of Service via inefficient certificate chain validation CVE-2026-33810 — crypto/x509: golang: Go crypto/x509: Certificate validation bypass due to incorrect DNS constraint application CVE-2026-33811 — net: golang: Go net package: Denial of Service via long CNAME response in LookupCNAME CVE-2026-33818 — encoding/asn1: golang: Go encoding/asn1: Denial of Service via excessive recursion in Unmarshal CVE-2026-39821 — golang.org/x/net/idna: golang: net/http: golang.org/x/net/idna: Privilege escalation via incorrect Punycode label processing CVE-2026-42504 — mime: golang: Golang MIME: Denial of Service via maliciously-crafted MIME header CVE-2026-56853 — net/http: golang: Go net/http: Unencrypted HTTP/2 connections vulnerable to Denial of Service CVE-2026-56859 — encoding/xml: golang: Go: Denial of Service via XML decoding recursion depth issue CVE-2026-56860 — net/url: golang: golang net/url: Denial of Service from quadratic complexity in path resolution CVE-2026-56862 — crypto/tls: golang: Golang crypto/tls: Denial of Service via indefinite KeyUpdate messages
🎯 Affected products14
- Red Hat Enterprise Linux AppStream EUS (v. 10.0)
- golang-github-openprinting-ipp-usb-0:0.9.27-3.el10_0.5.src as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
- golang-github-openprinting-ipp-usb-debugsource-0:0.9.27-3.el10_0.5.aarch64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
- golang-github-openprinting-ipp-usb-debugsource-0:0.9.27-3.el10_0.5.ppc64le as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
- golang-github-openprinting-ipp-usb-debugsource-0:0.9.27-3.el10_0.5.s390x as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
- golang-github-openprinting-ipp-usb-debugsource-0:0.9.27-3.el10_0.5.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
- ipp-usb-0:0.9.27-3.el10_0.5.aarch64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
- ipp-usb-0:0.9.27-3.el10_0.5.ppc64le as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
- ipp-usb-0:0.9.27-3.el10_0.5.s390x as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
- ipp-usb-0:0.9.27-3.el10_0.5.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
- ipp-usb-debuginfo-0:0.9.27-3.el10_0.5.aarch64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
- ipp-usb-debuginfo-0:0.9.27-3.el10_0.5.ppc64le as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
- ipp-usb-debuginfo-0:0.9.27-3.el10_0.5.s390x as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
- ipp-usb-debuginfo-0:0.9.27-3.el10_0.5.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
✅ 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: 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: 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: 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 issue, restrict network access to services that process MIME headers from untrusted sources. Implement input validation and sanitization for all incoming data, especially MIME headers, to prevent maliciously crafted content from being processed by applications utilizing the vulnerable Golang MIME package.
🔗 References (14)
- selfhttps://access.redhat.com/errata/RHSA-2026:98108
- externalhttps://access.redhat.com/security/updates/classification/#important
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2456333
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2456335
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2467822
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2480756
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2484204
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2484207
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2515815
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2515820
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2515827
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2515839
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2515840
- selfhttps://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_98108.json