CVE-2026-27145
Public on 2026-06-02
Modified on 2026-06-05
Description
(*x509.Certificate).VerifyHostname previously called matchHostnames in a loop over all DNS Subject Alternative Name (SAN) entries. This caused strings.Split(host, ".") to execute repeatedly on the same input hostname. With a large DNS SAN list, verification costs scaled quadratically based on the number of SAN entries multiplied by the hostname's label count. Because x509.Verify validates hostnames before building the certificate chain, this overhead occurred even for untrusted certificates.
CVSS v3 Base Score
See breakdown
Affected Packages
| Platform | Package | Release Date | Advisory | Status |
|---|---|---|---|---|
| Amazon Linux 2 - Core | amazon-cloudwatch-agent | Pending Fix | ||
| Amazon Linux 2023 | amazon-cloudwatch-agent | Pending Fix | ||
| Amazon Linux 2 - Aws-nitro-enclaves-cli Extra | amazon-ecr-credential-helper | Pending Fix | ||
| Amazon Linux 2 - Docker Extra | amazon-ecr-credential-helper | Pending Fix | ||
| Amazon Linux 2 - Ecs Extra | amazon-ecr-credential-helper | Pending Fix | ||
| Amazon Linux 2023 | amazon-ecr-credential-helper | Pending Fix | ||
| Amazon Linux 2 - Core | amazon-ssm-agent | Pending Fix | ||
| Amazon Linux 2023 | amazon-ssm-agent | Pending Fix | ||
| Amazon Linux 2 - Core | cni-plugins | Pending Fix | ||
| Amazon Linux 2023 | cni-plugins | Pending Fix | ||
| Amazon Linux 2 - Aws-nitro-enclaves-cli Extra | containerd | Pending Fix | ||
| Amazon Linux 2 - Docker Extra | containerd | Pending Fix | ||
| Amazon Linux 2 - Ecs Extra | containerd | Pending Fix | ||
| Amazon Linux 2023 | containerd | Pending Fix | ||
| Amazon Linux 2023 | credentials-fetcher | Pending Fix | ||
| Amazon Linux 2 - Core | cri-tools | Pending Fix | ||
| Amazon Linux 2 - Aws-nitro-enclaves-cli Extra | docker | Pending Fix | ||
| Amazon Linux 2 - Docker Extra | docker | Pending Fix | ||
| Amazon Linux 2 - Ecs Extra | docker | Pending Fix | ||
| Amazon Linux 2023 | docker | Pending Fix | ||
| Amazon Linux 2 - Ecs Extra | ecs-init | Pending Fix | ||
| Amazon Linux 2023 | ecs-init | Pending Fix | ||
| Amazon Linux 2023 | git-lfs | Pending Fix | ||
| Amazon Linux 2 - Core | golang | Pending Fix | ||
| Amazon Linux 2 - Golang1.11 Extra | golang | No Fix Planned | ||
| Amazon Linux 2 - Golang1.19 Extra | golang | No Fix Planned | ||
| Amazon Linux 2 - Golang1.9 Extra | golang | No Fix Planned | ||
| Amazon Linux 2023 | golang | Pending Fix | ||
| Amazon Linux 2023 | golang-github-burntsushi-toml | Pending Fix | ||
| Amazon Linux 2023 | golang-github-burntsushi-toml-test | Pending Fix | ||
| Amazon Linux 2023 | golang-github-cpuguy83-md2man | Pending Fix | ||
| Amazon Linux 2 - Core | golist | Pending Fix | ||
| Amazon Linux 2023 | golist | Pending Fix | ||
| Amazon Linux 2023 | libcap | Pending Fix | ||
| Amazon Linux 2 - Core | nerdctl | Pending Fix | ||
| Amazon Linux 2023 | nerdctl | Pending Fix | ||
| Amazon Linux 2 - Aws-nitro-enclaves-cli Extra | oci-add-hooks | Pending Fix | ||
| Amazon Linux 2 - Docker Extra | oci-add-hooks | Pending Fix | ||
| Amazon Linux 2 - Ecs Extra | oci-add-hooks | Pending Fix | ||
| Amazon Linux 2023 | oci-add-hooks | Pending Fix | ||
| Amazon Linux 2 - Core | rclone | Pending Fix | ||
| Amazon Linux 2023 | rclone | Pending Fix | ||
| Amazon Linux 2 - Aws-nitro-enclaves-cli Extra | runc | Pending Fix | ||
| Amazon Linux 2 - Docker Extra | runc | Pending Fix | ||
| Amazon Linux 2 - Ecs Extra | runc | Pending Fix | ||
| Amazon Linux 2023 | runc | Pending Fix | ||
| Amazon Linux 2 - Docker Extra | runfinch-finch | Pending Fix | ||
| Amazon Linux 2023 | runfinch-finch | Pending Fix | ||
| Amazon Linux 2 - Docker Extra | soci-snapshotter | Pending Fix | ||
| Amazon Linux 2023 | soci-snapshotter | Pending Fix | ||
| Amazon Linux 2023 | yq | Pending Fix |
CVSS Scores
| Score Type | Score | Vector | |
|---|---|---|---|
| Amazon Linux | CVSSv3 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |