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Vol. 1 · Ed. 2026
CyberGlossary
Entry № 155

CAA Record (Certification Authority Authorization)

Qu'est-ce que CAA Record (Certification Authority Authorization) ?

CAA Record (Certification Authority Authorization)A DNS record type (RFC 8659) that lets a domain owner restrict which Certificate Authorities are allowed to issue certificates for the domain, blocking accidental or malicious mis-issuance by other CAs.


A CAA record (Certification Authority Authorization, originally RFC 6844 and updated by RFC 8659) is a DNS resource record that lets a domain owner enumerate exactly which CAs may issue certificates for the domain. The record carries three fields: a flag byte, a property tag (`issue`, `issuewild`, `iodef`), and a value (typically a CA's issuer name such as `letsencrypt.org` or `digicert.com`). Since September 2017, all CAB Forum-trusted public CAs are required by the Baseline Requirements to check CAA records before issuing certificates and to refuse issuance if the record forbids them. A typical hardened deployment looks like `example.com. CAA 0 issue "letsencrypt.org"; example.com. CAA 0 issuewild ";"; example.com. CAA 0 iodef "mailto:security@example.com"`. The third record asks misbehaving CAs to report any rejected issuance attempt. CAA significantly reduces the risk of cert mis-issuance — by typosquatted domains, by hijacked CA accounts, by lookalike-CAs in obscure trust stores — and is one of the simplest single-record web-hygiene wins available. It pairs naturally with Certificate Transparency monitoring.

Exemples

  1. 01

    An organization publishes `CAA 0 issue "letsencrypt.org"` so that no other public CA can issue end-entity certificates for the domain.

  2. 02

    A CT-monitoring alert fires on a certificate issued for the domain by a CA not listed in its CAA records, indicating either a misconfiguration or a CA non-compliance event.

Questions fréquentes

Qu'est-ce que CAA Record (Certification Authority Authorization) ?

A DNS record type (RFC 8659) that lets a domain owner restrict which Certificate Authorities are allowed to issue certificates for the domain, blocking accidental or malicious mis-issuance by other CAs. Cette notion relève de la catégorie Sécurité réseau en cybersécurité.

Que signifie CAA Record (Certification Authority Authorization) ?

A DNS record type (RFC 8659) that lets a domain owner restrict which Certificate Authorities are allowed to issue certificates for the domain, blocking accidental or malicious mis-issuance by other CAs.

Comment fonctionne CAA Record (Certification Authority Authorization) ?

A CAA record (Certification Authority Authorization, originally RFC 6844 and updated by RFC 8659) is a DNS resource record that lets a domain owner enumerate exactly which CAs may issue certificates for the domain. The record carries three fields: a flag byte, a property tag (`issue`, `issuewild`, `iodef`), and a value (typically a CA's issuer name such as `letsencrypt.org` or `digicert.com`). Since September 2017, all CAB Forum-trusted public CAs are required by the Baseline Requirements to check CAA records before issuing certificates and to refuse issuance if the record forbids them. A typical hardened deployment looks like `example.com. CAA 0 issue "letsencrypt.org"; example.com. CAA 0 issuewild ";"; example.com. CAA 0 iodef "mailto:security@example.com"`. The third record asks misbehaving CAs to report any rejected issuance attempt. CAA significantly reduces the risk of cert mis-issuance — by typosquatted domains, by hijacked CA accounts, by lookalike-CAs in obscure trust stores — and is one of the simplest single-record web-hygiene wins available. It pairs naturally with Certificate Transparency monitoring.

Comment se défendre contre CAA Record (Certification Authority Authorization) ?

Les défenses contre CAA Record (Certification Authority Authorization) combinent habituellement des contrôles techniques et des pratiques opérationnelles, comme détaillé dans la définition ci-dessus.

Quels sont les autres noms de CAA Record (Certification Authority Authorization) ?

Noms alternatifs courants : Certification Authority Authorization, CAA DNS record.

Termes liés