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Fencer Vulns
high 7.5

CVE-2025-66564 json

Sigstore Timestamp Authority allocates excessive memory during request parsing

published 2025-12-04 11 mo ago modified 2026-10-18 21 d ago also GHSA-4qg8-fj49-pxjh , GO-2025-4192 , EUVD-2025-201319

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits
0
none known

Summary

Sigstore Timestamp Authority is a service for issuing RFC 3161 timestamps. Prior to 2.0.3, Function api.ParseJSONRequest currently splits (via a call to strings.Split) an optionally-provided OID (which is untrusted data) on periods. Similarly, function api.getContentType splits the Content-Type header (which is also untrusted data) on an application string. As a result, in the face of a malicious request with either an excessively long OID in the payload containing many period characters or a malformed Content-Type header, a call to api.ParseJSONRequest or api.getContentType incurs allocations of O(n) bytes (where n stands for the length of the function's argument). This vulnerability is fixed in 2.0.3.

Patch / fix

  • go github.com/sigstore/timestamp-authority 2.0.3
  • go github.com/sigstore/timestamp-authority/v2 2.0.3
  • linuxfoundation sigstore_timestamp_authority 2.0.3
  • golang-github-sigstore-timestamp-authority Debian 14 2.0.3-1

debian advisories DEBIAN-CVE-2025-66564

  • govulncheck-vulndb SLE Module for Package Hub 15 SP6, openSUSE Leap 15.6 0.0.20251209T172047-150000.1.127.1

suse advisories SUSE-SU-2025:4395-1

  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
  • trivy openSUSE Tumbleweed 0.69.0-1.1

opensuse advisories openSUSE-SU-2026:21483-1openSUSE-SU-2026:10131-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-66564 updated cvss 7.5

github.com/sigstore/timestamp-authority: Sigstore Timestamp Authority: Denial of Service via excessive OID or Content-Type header parsing

  • Red Hat OpenShift Pipelines openshift-pipelines-client, openshift-pipelines/pipelines-opc-rhel9, openshift-pipelines/pipelines-cli-tkn-rhel8, openshift-pipelines/pipelines-rhel8-operator, openshift-pipelines/pipelines-rhel9-operator, openshift-pipelines/pipelines-operator-bundle, +4 more
    affected: no fix available, no fix planned “Will not fix”
  • Red Hat OpenShift Serverless openshift-serverless-1/kn-plugin-event-sender-rhel9
    affected: no fix planned “Will not fix”
  • Red Hat Advanced Cluster Security 4 advanced-cluster-security/rhacs-operator-bundle Red Hat OpenShift Dev Spaces devspaces/udi-rhel9
    affected: no fix available
  • Red Hat Zero Trust Workload Identity Manager - Tech Preview zero-trust-workload-identity-manager/spiffe-spire-agent-rhel9, zero-trust-workload-identity-manager/spiffe-spire-server-rhel9, zero-trust-workload-identity-manager/spiffe-spire-oidc-discovery-provider-rhel9, zero-trust-workload-identity-manager/zero-trust-workload-identity-manager-rhel9, zero-trust-workload-identity-manager/zero-trust-workload-identity-manager-operator-bundle
    affected: no fix available, no fix planned “Will not fix”
  • Red Hat Advanced Cluster Security 4.8 advanced-cluster-security 1769615659
    fixed: vendor fix RHSA-2026:1517
  • Red Hat Advanced Cluster Security 4.9 advanced-cluster-security 1770074713, advanced-cluster-security 1770250889
    fixed: vendor fix RHSA-2026:2350
  • Red Hat OpenShift Pipelines 1.2 openshift-pipelines 1771374749, openshift-pipelines 1772679439, openshift-pipelines 1772694865
    fixed: vendor fix RHSA-2026:3825
  • Red Hat OpenShift Pipelines 1.15 openshift-pipelines 1772093872
    fixed: vendor fix RHSA-2026:3710
show 5 more
  • Red Hat Trusted Artifact Signer 1.3 rhtas 1770107440, rhtas 1771324865
    fixed: vendor fix RHSA-2026:3087
  • Red Hat Security Profiles Operator 1 compliance 1770869850, compliance 1771367226
    fixed: vendor fix RHSA-2026:2852
  • Red Hat Advanced Cluster Security 4 advanced-cluster-security/rhacs-roxctl-rhel8, advanced-cluster-security/rhacs-collector-rhel8, advanced-cluster-security/rhacs-central-db-rhel8, advanced-cluster-security/rhacs-scanner-v4-rhel8, advanced-cluster-security/rhacs-scanner-v4-db-rhel8 Red Hat Advanced Cluster Security 4.8 advanced-cluster-security 1769010086, advanced-cluster-security 1769125501, advanced-cluster-security 1769615659 Red Hat Advanced Cluster Security 4.9 advanced-cluster-security 1769065259, advanced-cluster-security 1769100379, advanced-cluster-security 1769492398, advanced-cluster-security 1769577723, advanced-cluster-security 1770074713, advanced-cluster-security 1770250889 Red Hat OpenShift Container Platform 4 openshift4/ose-aws-cluster-api-controllers-rhel9, openshift4/ose-ibmcloud-cluster-api-controllers-rhel9 Red Hat OpenShift Pipelines 1.2 openshift-pipelines 1770988020, openshift-pipelines 1771361514, openshift-pipelines 1771361580, openshift-pipelines 1771374322, openshift-pipelines 1771374358, openshift-pipelines 1771374363, +23 more Red Hat OpenShift Pipelines 1.15 openshift-pipelines 1771425314, openshift-pipelines 1771510606, openshift-pipelines 1771964016, openshift-pipelines 1771964021, openshift-pipelines 1771964042, openshift-pipelines 1771964076, +18 more
    not affected: vulnerable code not present
  • Red Hat Trusted Artifact Signer rhtas/cosign-rhel9, rhtas/gitsign-rhel9, rhtas/client-server-rhel9, rhtas/policy-controller-rhel9
    not affected: vulnerable code not in execute path
  • Red Hat Trusted Artifact Signer 1.3 rhtas 1770106156, rhtas 1770106163, rhtas 1770107446, rhtas 1770107452, rhtas 1770107577, rhtas 1771324807 Red Hat Security Profiles Operator 1 compliance 1771365778, compliance 1771365810, compliance 1771365824
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
11 mo ago

Exploit prediction

0.47% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
go github.com/sigstore/timestamp-authority
<2.0.3
all versions
2.0.3
go github.com/sigstore/timestamp-authority/v2
<2.0.3
2.0.3

Affected products

  • sigstore timestamp-authority

Classification

Weakness
  • CWE-405 Asymmetric Resource Consumption (Amplification)

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.