Skip to content
OpenAdvisories
High ALSA-2026:48790 5 CVEs

Important: osbuild-composer security update

Published Jul 30, 2026 · Updated Oct 29, 2026

Ecosystem: AlmaLinux

Summary

A service for building customized OS artifacts, such as VM images and OSTree commits, that uses osbuild under the hood. Besides building images for local usage, it can also upload images directly to cloud. It is compatible with composer-cli and cockpit-composer clients.

Security Fix(es):

* google.golang.org/grpc/grpc-go: google.golang.org/grpc/authz: gRPC-Go: Authorization bypass due to improper HTTP/2 path validation (CVE-2026-33186)
* github.com/go-jose/go-jose/v3: github.com/go-jose/go-jose/v4: Go JOSE: Denial of Service via crafted JSON Web Encryption (JWE) object (CVE-2026-34986)
* golang: internal/syscall/unix: Root.Chmod can follow symlinks out of the root (CVE-2026-32282)
* crypto/tls: golang: Go crypto/tls: Denial of Service via multiple TLS 1.3 key update messages (CVE-2026-32283)
* crypto/x509: crypto/tls: golang: Go: Denial of Service vulnerability in certificate chain building (CVE-2026-32280)

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.

Fixed packages 3

ReleasePackageFixed in
AlmaLinux · 8 osbuild-composer 101.5-1.el8_10.alma.1
AlmaLinux · 8 osbuild-composer-core 101.5-1.el8_10.alma.1
AlmaLinux · 8 osbuild-composer-worker 101.5-1.el8_10.alma.1

Vulnerabilities 5

  • Critical 9.1
    CVE-2026-33186 Public exploit

    gRPC-Go has an authorization bypass via missing leading slash in :path

    gRPC-Go is the Go language implementation of gRPC. Versions prior to 1.79.3 have an authorization bypass resulting from improper input validation of the HTTP/2 `:path` pseudo-header. The gRPC-Go server was too lenient in its routing logic, accepting requests …

    grpc grpc-go zot kubescape Debian Ubuntu Alpine Wolfi Go
  • High 7.5
    CVE-2026-32280

    Unexpected work during chain building in crypto/x509

    During chain building, the amount of work that is done is not correctly limited when a large number of intermediate certificates are passed in VerifyOptions.Intermediates, which can lead to a denial of service. This affects both direct users of crypto/x509 an…

    Go standard library crypto/x509 golang go Debian Ubuntu Azure Linux Alpine Wolfi Go
  • High 7.5
    CVE-2026-32283

    Unauthenticated TLS 1.3 KeyUpdate record can cause persistent connection retention and DoS in crypto/tls

    If one side of the TLS connection sends multiple key update messages post-handshake in a single record, the connection can deadlock, causing uncontrolled consumption of resources. This can lead to a denial of service. This only affects TLS 1.3.

    Go standard library crypto/tls golang go Debian Ubuntu Azure Linux Alpine Wolfi Go
  • High 7.5
    CVE-2026-34986

    Go JOSE affect by a panic in JWE decryption

    Go JOSE provides an implementation of the Javascript Object Signing and Encryption set of standards in Go, including support for JSON Web Encryption (JWE), JSON Web Signature (JWS), and JSON Web Token (JWT) standards. Prior to 4.1.4 and 3.0.5, decrypting a JS…

    go-jose go-jose zot kubescape Debian Ubuntu Alpine Wolfi Go
  • Medium 6.4
    CVE-2026-32282

    TOCTOU permits root escape on Linux via Root.Chmod in os in internal/syscall/unix

    On Linux, if the target of Root.Chmod is replaced with a symlink while the chmod operation is in progress, Chmod can operate on the target of the symlink, even when the target lies outside the root. The Linux fchmodat syscall silently ignores the AT_SYMLINK_N…

    Go standard library internal/syscall/unix golang go Debian Ubuntu Azure Linux Alpine Wolfi Go

References

  • report
    https://access.redhat.com/security/cve/CVE-2026-32280
  • report
    https://access.redhat.com/security/cve/CVE-2026-32282
  • report
    https://access.redhat.com/security/cve/CVE-2026-32283
  • report
    https://access.redhat.com/security/cve/CVE-2026-33186
  • report
    https://access.redhat.com/security/cve/CVE-2026-34986
  • report
    https://bugzilla.redhat.com/2449833
  • report
    https://bugzilla.redhat.com/2455470
  • report
    https://bugzilla.redhat.com/2456336
  • report
    https://bugzilla.redhat.com/2456338
  • report
    https://bugzilla.redhat.com/2456339
  • advisory
    https://errata.almalinux.org/8/ALSA-2026-48790.html