Описание
A flaw was found in gnutls. When validating certificates, an oversized Subject Alternative Name (SAN) could cause the validation process to incorrectly fall back to checking the Common Name (CN) field. This could allow a remote attacker to bypass proper certificate validation, potentially leading to spoofing or man-in-the-middle attacks.
Отчет
This vulnerability is rated as having a Moderate impact across affected Red Hat products because successful exploitation requires an active man-in-the-middle network position as well as a certificate issued by a trusted authority matching the target hostname's Common Name. Although TLS clients using GnuTLS on Red Hat Enterprise Linux and OpenShift are susceptible to improper certificate acceptance under these conditions, modern certificate authorities rarely issue certificates that omit valid Subject Alternative Names, substantially restricting practical threat vectors. Applications functioning exclusively as TLS servers or utilizing alternative cryptographic libraries like OpenSSL are not exposed to this flaw.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 6 | gnutls | Out of support scope | ||
| Red Hat OpenShift Container Platform 4 | openshift4/ose-hypershift-rhel9 | Not affected | ||
| Red Hat OpenShift Container Platform 5 | openshift/ose-rhel-coreos-9 | Affected | ||
| Red Hat Enterprise Linux 10 | gnutls | Fixed | RHSA-2026:20613 | 26.05.2026 |
| Red Hat Enterprise Linux 10.0 Extended Update Support | gnutls | Fixed | RHSA-2026:26409 | 16.06.2026 |
| Red Hat Enterprise Linux 7 Extended Lifecycle Support | gnutls | Fixed | RHSA-2026:43575 | 22.07.2026 |
| Red Hat Enterprise Linux 8 | gnutls | Fixed | RHSA-2026:20611 | 26.05.2026 |
| Red Hat Enterprise Linux 8 | gnutls | Fixed | RHSA-2026:20611 | 26.05.2026 |
| Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | gnutls | Fixed | RHSA-2026:33125 | 29.06.2026 |
| Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | libtasn1 | Fixed | RHSA-2026:33125 | 29.06.2026 |
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Дополнительная информация
Статус:
EPSS
8.2 High
CVSS3
Связанные уязвимости
A flaw was found in gnutls. When validating certificates, an oversized Subject Alternative Name (SAN) could cause the validation process to incorrectly fall back to checking the Common Name (CN) field. This could allow a remote attacker to bypass proper certificate validation, potentially leading to spoofing or man-in-the-middle attacks.
A flaw was found in gnutls. When validating certificates, an oversized Subject Alternative Name (SAN) could cause the validation process to incorrectly fall back to checking the Common Name (CN) field. This could allow a remote attacker to bypass proper certificate validation, potentially leading to spoofing or man-in-the-middle attacks.
Gnutls: gnutls: certificate validation bypass due to oversized subject alternative name
A flaw was found in gnutls. When validating certificates, an oversized ...
EPSS
8.2 High
CVSS3