2072600 - Firmaprofesional: Delayed revocation of SHA-1-signed AC Firmaprofesional - CA1

Status: ASSIGNED

(CA Program :: CA Certificate Compliance, task)

Description

[Chema]

Preliminary Incident Report

Summary

• Incident description:

  Firmaprofesional did not revoke the unexpired subordinate CA certificate AC Firmaprofesional - CA1 before the 2026-09-15 deadline specified in TLS Baseline Requirements Section 7.1.3.2.1 for subordinate CA certificates signed using RSASSA-PKCS1-v1_5 with SHA-1.

  Firmaprofesional received a Certificate Problem Report from the Chrome Root Program on 2026-09-15 15:18:37 UTC, identifying CA1 as unexpired and unrevoked after the SHA-1 retirement deadline. Review confirmed that the certificate is signed with sha1WithRSAEncryption.

  On 2026-09-16 05:48:19 UTC, Firmaprofesional replied to the Chrome Root Program, acknowledging the explicit revocation requirement and stating that CA1's revocation status was under urgent investigation. The reply committed to follow up with verified findings and the necessary actions and timeline.

  The currently confirmed affected subordinate CA certificate is:

  Field	Value
  Subject common name	AC Firmaprofesional - CA1
  Issuer common name	Autoridad de Certificacion Firmaprofesional CIF A62634068
  SHA-256 fingerprint	0EBBDF146E63F70FAA5927EE8E5346E9C96C5F0D9BDD3212B04ED6687179874D
  Serial number (hexadecimal)	533015E09A9EB866
  Not before	2009-08-25 10:05:54 UTC
  Not after	2030-06-16 10:05:54 UTC
  Signature algorithm	sha1WithRSAEncryption

  As of 2026-09-16, CA1 has no currently valid TLS server authentication certificates. Its remaining valid end-entity certificates are four timestamping certificates and one OCSP responder certificate. The absence of currently valid TLS server certificates does not remove the subordinate CA revocation requirement.

  CA1's revocation and its publication has not been completed. The incident is therefore considered ongoing. Revocation of dependent certificates has begun according to operational reporting; the individual revocation timestamps and their publication are being reconciled before they are included as verified remediation milestones. These actions do not by themselves complete revocation of CA1.

  The reason the SHA-1 retirement deadline was missed has not yet been established. The investigation must address policy-change tracking, inventory coverage, detection, and revocation planning. The Full Incident Report will provide the verified timeline, root cause analysis, final scope, remediation evidence, and preventive actions with owners and due dates. It will be published within 14 days of this initial public disclosure.

• Relevant policies:

  • TLS Baseline Requirements, Section 7.1.3.2.1: requires revocation of unexpired SHA-1-signed subordinate CA certificates before 2026-09-15.
  • Ballot SC-097: SHA-1 retirement requirements.
  • Chrome Root Program Policy, Section 1.5.1: public incident reporting and reporting of missed required follow-up actions.
  • CCADB Incident Reporting Guidelines: incident scope, delayed-revocation reporting, format and timelines.

• Source of incident disclosure:

  Third Party Reported — Chrome Root Program.

Comment 1

[Chema]

Status Update — 2026-09-23

The incident remains ongoing. Revocation of AC Firmaprofesional - CA1 has not yet been completed.

The remaining operational dependencies concern a subset of TSA certificates used for eIDAS qualified timestamping services. Customer communications and technical coordination have progressed, including arrangements for access needed to assess replacement options. Responses and technical assessments remain outstanding, and the transition has not yet been completed.

This work also considers continued availability of certificate-status information and the measures needed to support validation of previously generated evidence. These operational considerations do not alter the requirement to revoke CA1 or the deadline already missed.

We do not yet have a confirmed completion date for CA1’s revocation. We will publish a verified estimate as soon as it is available.

We will publish the Full Incident Report by 2026-09-30.

Comment 2

[Chema]

Full Incident Report

Summary

• CA Owner CCADB unique ID: A000006 — Firmaprofesional.

• Incident description: Firmaprofesional failed to revoke the AC Firmaprofesional - CA1 subordinate CA certificate, which is signed with SHA-1 and remains within its validity period, before 2026-09-15 as required by Section 7.1.3.2.1 of the TLS Baseline Requirements. The certificate remains unrevoked, so the incident is ongoing.

• Timeline summary:

  • Non-compliance start date: 2026-09-15, when CA1 remained unrevoked after the applicable deadline.
  • Non-compliance identified date: 2026-09-15 at 15:18:37 UTC, upon receipt of the Certificate Problem Report from the Chrome Root Program.
  • Non-compliance end date: Ongoing. It will end when CA1 has been revoked and the revocation has been verified in the applicable public status information.

• Relevant policies: TLS BR §7.1.3.2.1, SC-097, and CCADB Incident Reporting Guidelines.

• Source of incident disclosure: third party — Chrome Root Program.

Impact

• Total number of certificates: 1 subordinate CA certificate, AC Firmaprofesional - CA1, is directly affected by the non-compliance. Four time-stamping certificates issued by CA1 are operational dependencies of the revocation plan but are not counted as certificates directly non-compliant with TLS BR §7.1.3.2.1.
• Total number of "remaining valid" certificates: 1. The CA1 certificate remains within its validity period and has not been revoked.
• Affected certificate types: SHA-1-signed subordinate CA certificate.
• Incident heuristic: An unexpired CA certificate signed using sha1WithRSAEncryption that had not been revoked before 2026-09-15. The affected certificate is uniquely identified by SHA-256 fingerprint 0EBBDF146E63F70FAA5927EE8E5346E9C96C5F0D9BDD3212B04ED6687179874D.
• Was issuance stopped in response to this incident, and why or why not?: No additional issuance stop was required. CA1 was already technically disabled from issuing new certificates of any type, and its last certificate was issued on 2022-11-02.
• Analysis: CA1 has no currently valid TLS server authentication certificates. This limits the current WebPKI impact but does not remove the revocation requirement or excuse the missed deadline.
• Additional considerations: Four time-stamping certificates issued by CA1 remain operational dependencies. Revocation may change the technical validation outcome, or how that outcome is presented, for documents containing time-stamps issued with those certificates, particularly PDF documents. Firmaprofesional is therefore coordinating a controlled sequence for their transition and revocation, followed by the revocation of CA1, and is evaluating measures to preserve the certificate-status and validation information needed for time-stamps issued before revocation. This coordination does not change the requirement, its deadline, or make revocation conditional on customer agreement. The expiry dates of the four dependent certificates are 2027-12-11, 2029-10-22 and, for two certificates, 2030-06-16. A final incident-completion date has not yet been established; the next planning milestone is 2026-10-09. The public report does not identify certificate holders or organizations.

Timeline

Date and time UTC	Event
2009-08-25 10:05:54	Start of the CA1 certificate validity period. This is not presented as the verified time of the issuance operation.
2022-11-02	Date of the last certificate issued by CA1.
2026-09-07 06:42:10	Publication of Comment 8 in Bug 2054448: context concerning the incomplete migration of the legacy hierarchy and dependencies of non-TLS services.
2026-09-15	CA1 remained unrevoked after the applicable deadline; the incident began.
2026-09-15 15:18:37	Receipt of the Chrome Root Program CPR concerning the SHA-1 signature and the absence of the certificate fingerprint from the referenced audit statements.
2026-09-15	Firmaprofesional identified five time-stamping, an OCSP responder and 19 end-user certificates as the remaining operational dependencies under CA1 and began assessing the impact of their revocation.
2026-09-16	Revocation of one time-stamping certificiate and 19 end-user certificates.
2026-09-16 up to date	Assessment of the time-stamping dependencies, transition alternatives, and measures to preserve validation information for previous time-stamps.

Related Incidents

Case	Opening date	Relationship
Bug 1651632 — Microsec: Failure to revoke noncompliant ICA within 7 days	2020-07-09	Historical precedent involving revocation of CA certificates related to time-stamping and the resulting document-validation dependencies. It is relevant to controlled transition and preservation of validation evidence for a service other than TLS; the original issue involved EKU/OCSP, not SHA-1.
Bug 2047337 — Government of Korea: Delayed revocation related to Bugzilla 2032478	2026-06-13	Delayed-revocation case under a legacy hierarchy. It is relevant to linking transition activities to a schedule and verifiable revocation status. It affected TLS Subscriber Certificates, not time-stamping certificates.
Bug 2072663 — GoDaddy: Delayed Revocation of SHA-1 Signed Subordinate CA Certificates	2026-09-16	Incident under the same TLS BR §7.1.3.2.1 requirement. Two legacy SHA-1-signed subordinate CAs, historically used to issue SSL/TLS certificates, had not issued certificates for several years. Although removal of the legacy roots from Root Stores was already being managed, GoDaddy concluded that the CAs had to be revoked and revoked them on 2026-09-17.
Bug 2073233 — FNMT: Delayed Revocation of SHA-1 Signed Subordinate CA Certificate	2026-09-17	Incident under the same TLS BR §7.1.3.2.1 requirement. FNMT’s FIR, published on 2026-09-29, limits the affected corpus to a legacy SHA-1-signed intermediate CA that was no longer being used to issue certificates. FNMT concluded that it had to revoke the CA and executed the revocation on 2026-09-21.

Root Cause Analysis

Contributing Factor #1: Incomplete implementation of the SHA-1 revocation requirement

• Description: the regulatory-change process did not translate TLS BR §7.1.3.2.1 into a tracked revocation action for every unexpired SHA-1-signed CA certificate early enough to complete the required migrations and revoke CA1 before 2026-09-15. The incomplete migration of the legacy hierarchy and the unresolved time-stamping dependencies delayed execution.
• Timeline: the migration and dependency work was not completed before 2026-09-15. The incident was identified that day.
• Detection: the failure to revoke CA1 by the deadline was detected following the Certificate Problem Report received from the Chrome Root Program. The contributing factor was identified through review of the applicable requirement, the CA inventory, CA1’s issuance status, and its operational time-stamping dependencies.
• Interaction with other factors: no additional contributing factor was identified. The incomplete hierarchy migration and unresolved time-stamping dependencies are elements of this factor because the regulatory-change process did not bring them to resolution before the compliance deadline.
• Root Cause Analysis methodology used: regulatory-change process review, certificate-inventory review, and timeline analysis of the migration and revocation activities.

Lessons Learned

• What went well: Firmaprofesional responded to the CPR, published the Preliminary Incident Report, identified the complete population of remaining time-stamping dependencies, and began evaluating transition and validation-preservation measures.
• What didn’t go well: the regulatory-change process did not produce and complete a CA1 migration and revocation plan before the effective date. The later scope interpretation also failed to distinguish between limited current WebPKI impact and the applicability of the CA-certificate revocation requirement.
• Where we got lucky: CA1 had already stopped issuing certificates and had no currently valid TLS server authentication certificates when the deadline elapsed. This limited the active WebPKI exposure but did not reduce or remove the non-compliance.
• Additional: N/A.

Action Items

Action Item	Kind	Corresponding Root Cause(s)	Evaluation Criteria	Due Date	Status
Establish and execute a controlled plan for the transition and revocation of the four time-stamping certificates and the subsequent revocation of CA1, verifying the measures needed to preserve the validation information for previous time-stamps.	Mitigate	Contributing Factor #1	A dated schedule is approved; transition and validation measures are implemented and tested; all five revocations are verified in the applicable sources; progress is published in this ticket.	2026-10-09 planning milestone; final completion date pending	Ongoing

Firmaprofesional will continue to report transparently in this ticket on the verifiable progress of the action item and any change to the revocation schedule.

We request that the Whiteboard Next update date be set to 2026-10-07.

Appendix

CA1 Certificate

Field	Value
Subject common name	AC Firmaprofesional - CA1
Issuer common name	Autoridad de Certificacion Firmaprofesional CIF A62634068
SHA-256 fingerprint	0EBBDF146E63F70FAA5927EE8E5346E9C96C5F0D9BDD3212B04ED6687179874D
Serial number (hexadecimal)	533015E09A9EB866
Validity start	2009-08-25 10:05:54 UTC
Validity end	2030-06-16 10:05:54 UTC
Signature algorithm	sha1WithRSAEncryption
Revocation status	Unrevoked according to the latest available information; the non-compliance remains ongoing
Revocation date and CRL reason	Not yet available — revocation has not been completed
Public reference	crt.sh

Comment 3

[Chema]

Status Update — 2026-10-07

The incident remains ongoing. AC Firmaprofesional - CA1 has not yet been revoked.

Since the Full Incident Report was published, one additional time-stamping certificate issued by CA1 has been revoked. The revocation is included in CA1 CRL number 68020, with a revocation time of 2026-10-07 07:30:47 UTC and reason cessationOfOperation. The CRL has a thisUpdate value of 2026-10-07 07:33:53 UTC.

The current status of the five time-stamping certificates originally identified as operational dependencies is:

• Revoked: 2
• Not yet revoked: 3
• Expired before revocation: 0

Technical coordination and transition work concerning the remaining dependencies has progressed. This work continues to include the measures needed to preserve the certificate-status and validation information supporting time-stamps generated before revocation.

No verified estimate is currently available for completion of all remaining revocations. Firmaprofesional will continue to publish verifiable progress in this ticket. The incident will remain open until the remaining dependent certificates and CA1 have been revoked and their status has been verified in the applicable public sources.

Comment 4

[Chema]

Status Update — 2026-10-09

As stated in our previous update, the controlled transition and revocation of the remaining time-stamping certificates is still in progress.

A further time-stamping certificate is scheduled to be revoked on 2026-10-19.

For the other two remaining time-stamping certificates, we are coordinating with the affected customers to allow time for them to apply new time-stamps to documents they consider particularly important for long-term preservation and technical validation. These discussions concern time-stamps generated before revocation and the measures needed to preserve their supporting validation information.

This coordination is the reason why a definitive schedule for all remaining revocations, including the subsequent revocation of AC Firmaprofesional - CA1, has not yet been established. We are working toward completion over the coming weeks, but cannot currently confirm a final completion date. This does not alter the applicable revocation requirement or excuse the continuing delay.

The planning milestone established for 2026-10-09 has therefore not been met, and the Action Item status has been updated to Delayed.

Updated Action Item

Action Item	Kind	Corresponding Root Cause(s)	Evaluation Criteria	Due Date	Status
Establish and execute a controlled plan for the transition and revocation of the four time-stamping certificates and the subsequent revocation of CA1, verifying the measures needed to preserve the validation information for previous time-stamps.	Mitigate	Contributing Factor #1	A dated schedule is approved; transition and validation measures are implemented and tested; all five revocations are verified in the applicable sources; progress is published in this ticket.	2026-10-09 planning milestone missed; final completion date pending	Delayed

Firmaprofesional will continue to publish verifiable progress in this ticket. The incident remains ongoing until the remaining dependent certificates and CA1 have been revoked and their status has been verified in the applicable public sources.

We request that the Whiteboard Next update date be set to 2026-10-16. We will provide the next progress update by that date, or earlier if there is a material change.