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Documentation

Document Repository: https://letsencrypt.org/repository/

Problem Reporting

cert-prob-reports[at]letsencrypt[dot]org https://letsencrypt.org/contact/

Mozilla CA Program — Known Bugzilla Cases (48)

#2044788 ASSIGNED 2026-06-03

Let's Encrypt: CRLs Temporarily Missing Revoked Serials

#2038351 ASSIGNED 2026-05-08

Let's Encrypt: Gen Y Cross-Certified Subordinate CAs missing serverAuth EKU

#1972745 RESOLVED 2025-06-18

Let's Encrypt: Deployed Unreviewed Boulder Code

#1966515 RESOLVED 2025-05-14

Let's Encrypt: Issuance for Invalid Internationalized Domain Name

#1955721 RESOLVED 2025-03-21

Let's Encrypt: Failure to Document Analysis of Detected Vulnerabilities

#1954861 RESOLVED 2025-03-18

Let's Encrypt: Early CRL Removal Incident

#1921573 RESOLVED 2024-09-27

Let's Encrypt: No Meaningful Subject Distinguished Name

#1886876 RESOLVED 2024-03-21

Let's Encrypt: keyCompromise key blocking deviation from CP/CPS

#1863635 RESOLVED 2023-11-07

Let's Encrypt Draft WebTrust Audit Documents

#1853719 RESOLVED 2023-09-18

Once Revoked Let's Encrypt Certificate Actively Signing Malware

#1838667 RESOLVED 2023-06-15

Let's Encrypt: Duplicate Serial Numbers

#1802059 RESOLVED 2022-11-23

Let's Encrypt 2022 WebTrust Audit Documents

#1799755 RESOLVED 2022-11-08

Let's Encrypt: End Entity CRLs Not Reissued On Time

#1795483 RESOLVED 2022-10-14

Let's Encrypt: Delayed revocation for removed gTLD

#1793114 RESOLVED 2022-09-30

Let's Encrypt: Incomplete and Inconsistent CRLs

#1789521 RESOLVED 2022-09-06

Let's Encrypt: Certificates issued to Elliptic Curve Debian Weak Keys

#1753123 RESOLVED 2022-02-01

Let's Encrypt: Failure to provide OCSP Responses for some certificates

#1752670 RESOLVED 2022-01-29

Let's Encrypt: TLS Using ALPN Allows Additional Identifiers in Challenge Certificate

#1751984 RESOLVED 2022-01-25

Let's Encrypt: TLS Using ALPN TLS Version and OID

#1742704 RESOLVED 2021-11-23

Let's Encrypt: Potential Denial of Service against websites with broad private key reuse

#1735247 RESOLVED 2021-10-11

Let's Encrypt: Mis-issued certificates related to SC48v2

#1729567 RESOLVED 2021-09-07

Let's Encrypt: Delay updating OCSP responses

#1715672 RESOLVED 2021-06-10

Let's Encrypt: Failure to revoke for Certificate Lifetime Incident

#1715455 RESOLVED 2021-06-09

Let's Encrypt: certificate lifetimes 90 days plus one second

#1701317 RESOLVED 2021-03-26

ISRG Root X2 inclusion request

#1684112 RESOLVED 2020-12-23

Let's Encrypt: Failure to audit log subscriber certificate OCSP updates

#1666047 RESOLVED 2020-09-18

Let's Encrypt: 302 total OCSP responses available beyond acceptable timelines

#1658437 RESOLVED 2020-08-10

Let's Encrypt: intent to issue root and intermediate certificates with organizationName and CABF DV OID

#1648840 RESOLVED 2020-06-26

Let's Encrypt: OCSP responses with no revocationReason

#1645276 RESOLVED 2020-06-12

Let's Encrypt: Expired ISRG Root OCSP X1 Certificate

#1639794 RESOLVED 2020-05-21

Let's Encrypt: Failure to revoke key-compromised certificate within 24 hours

#1627614 RESOLVED 2020-04-06

Let's Encrypt: Failure to revoke key-compromised certificates within 24 hours

#1625322 RESOLVED 2020-03-26

Let's Encrypt: Failure to revoke key-compromised certificates within 24 hours

#1619179 RESOLVED 2020-03-02

Let's Encrypt: Incomplete revocation for CAA rechecking bug

#1619047 RESOLVED 2020-02-29

Let's Encrypt: CAA Rechecking bug

#1577652 RESOLVED 2019-08-29

Let's Encrypt: OCSP Responder Returned "Unauthorized" for Some Precertificates

#1576789 RESOLVED 2019-08-27

Let's Encrypt: 2019.08.20 Incident: Incorrect OCSP responses under certain conditions

#1486650 RESOLVED 2018-08-27

Let's Encrypt: OCSP "unauthorized" responses

#1462735 RESOLVED 2018-05-18

Let's Encrypt: Case-sensitive CAA tag processing

#1446080 RESOLVED 2018-03-15

Let's Encrypt: Improper encoding of wildcard certificates

#1441413 RESOLVED 2018-02-27

Audit documents for ISRG / Let's Encrypt

#1414039 RESOLVED 2017-11-02

Let's Encrypt: Attacker-controlled google.tg certificate being used in the wild.

#1398427 RESOLVED 2017-09-09

Let's Encrypt: CAA Misissuances

#1391867 RESOLVED 2017-08-19

Let's Encrypt: Non-BR-Compliant Certificate Issuance

#1341718 RESOLVED 2017-02-22

ISRG / Let's Encrypt WebTrust audits

#1319609 RESOLVED 2016-11-23

Let's Encrypt: certs issued contrary to CPS due to incomplete blocklist

#1230797 RESOLVED 2015-12-06

Distrust ISRG Subordinate Certificate and Remove It Until the CA is Compliant with Mozilla Policies

#1204656 RESOLVED 2015-09-14

Add ISRG / Let's Encrypt root certificate

Certificates (40)

ISRG Root X1

Root M: Included C: Included A: Included M: Included 2015-06-04 – 2035-06-04

ISRG Root X2

Root M: Included C: Included A: Included M: Included 2020-09-04 – 2040-09-17

Root YE

Root M: Not Yet Included C: Not Included A: Not Included M: Not Included 2025-09-03 – 2045-09-02

Root YR

Root M: Not Yet Included C: Not Included A: Not Included M: Not Included 2025-09-03 – 2045-09-02

Intermediate M: Not Trusted C: Not Trusted A: Not Trusted M: Not Trusted 2020-09-04 – 2025-09-15

Intermediate M: Trusted C: Trusted A: Trusted M: Trusted 2024-03-13 – 2027-03-12

ISRG Root X2

Intermediate M: Trusted C: Trusted A: Trusted M: Trusted 2026-05-13 – 2032-09-02

ISRG Root X2

Intermediate M: Not Trusted C: Not Trusted A: Not Trusted M: Not Trusted 2025-09-03 – 2032-09-02

ISRG Root X2

Intermediate M: Not Trusted C: Not Trusted A: Not Trusted M: Not Trusted 2020-09-04 – 2025-09-15

Let's Encrypt Authority X1

Intermediate M: Not Trusted C: Not Trusted A: Not Trusted M: Not Trusted 2015-06-04 – 2020-06-04

Let's Encrypt Authority X2

Intermediate M: Not Trusted C: Not Trusted A: Not Trusted M: Not Trusted 2015-06-04 – 2020-06-04

Let's Encrypt Authority X3

Intermediate M: Not Trusted C: Not Trusted A: Not Trusted M: Not Trusted 2016-10-06 – 2021-10-06

Let's Encrypt Authority X4

Intermediate M: Not Trusted C: Not Trusted A: Not Trusted M: Not Trusted 2016-10-06 – 2021-10-06

R10

Intermediate M: Trusted C: Trusted A: Trusted M: Trusted 2024-03-13 – 2027-03-12

R11

Intermediate M: Trusted C: Trusted A: Trusted M: Trusted 2024-03-13 – 2027-03-12

R12

Intermediate M: Trusted C: Trusted A: Trusted M: Trusted 2024-03-13 – 2027-03-12

R13

Intermediate M: Trusted C: Trusted A: Trusted M: Trusted 2024-03-13 – 2027-03-12

R14

Intermediate M: Trusted C: Trusted A: Trusted M: Trusted 2024-03-13 – 2027-03-12

Intermediate M: Not Trusted C: Not Trusted A: Not Trusted M: Not Trusted 2020-09-04 – 2025-09-15

Root YE

Intermediate M: Trusted C: Trusted A: Trusted M: Trusted 2026-05-13 – 2032-09-02

Root YE

Intermediate M: Not Trusted C: Not Trusted A: Not Trusted M: Not Trusted 2025-09-03 – 2032-09-02

Root YR

Intermediate M: Trusted C: Trusted A: Trusted M: Trusted 2026-05-13 – 2032-09-02

Root YR

Intermediate M: Not Trusted C: Not Trusted A: Not Trusted M: Not Trusted 2025-09-03 – 2032-09-02

YE1

Intermediate M: Trusted C: Trusted A: Trusted M: Trusted 2025-09-03 – 2028-09-02

YE2

Intermediate M: Trusted C: Trusted A: Trusted M: Trusted 2025-09-03 – 2028-09-02

YE3

Intermediate M: Trusted C: Trusted A: Trusted M: Trusted 2025-09-03 – 2028-09-02

YR1

Intermediate M: Trusted C: Trusted A: Trusted M: Trusted 2025-09-03 – 2028-09-02

YR2

Intermediate M: Trusted C: Trusted A: Trusted M: Trusted 2025-09-03 – 2028-09-02

YR3

Intermediate M: Trusted C: Trusted A: Trusted M: Trusted 2025-09-03 – 2028-09-02