CVE-2026-110985

Что произошло

A Kafka broker using SASL/OAUTHBEARER with the default validator (sasl.oauthbearer.jwt.validator.class=DefaultJwtValidator) selects its implementation from configuration. When sasl.oauthbearer.jwks.endpoint.url is set, the validator verifies the JWT signature. When that URL is unset (the default) and no verification key resolver is supplied, DefaultJwtValidator silently falls back to ClientJwtValidator, which does not verify the JWT signature, algorithm, or issuer - and the broker starts with no warning or error. This is the residual of CVE-2026-33557, whose fix restored signature verification only on the path where the JWKS endpoint URL is set. Impact: A broker in this state accepts any structurally valid JWT, including "alg":"none" tokens. An unauthenticated remote attacker who can reach the listener can forge a token asserting any principal - including configured superusers - and gain full access to the cluster. Only brokers that enable SASL/OAUTHBEARER validation without a JWKS endpoint URL (and without a custom verification key resolver) are affected; brokers that set the URL verify signatures and are not affected. Unlike CVE-2026-110952 (issuer/audience not enforced by default), here no signature is verified at all. Mitigation (all affected versions, no upgrade required): Set sasl.oauthbearer.jwks.endpoint.url for every listener/mechanism that uses OAuthBearerValidatorCallbackHandler, or configure a signature-verifying sasl.oauthbearer.jwt.validator.class. Resolution: From Apache Kafka 4.2.2, 4.3.1, and 4.4.0: a broker that would fall back to the non-verifying ClientJwtValidator fails to start with a ConfigException instead of running without signature verification (secure by default).

Что делать

dpkg-query -W -f='${Package}	${Version}\n'

rpm -qa --qf '%{NAME}\t%{VERSION}-%{RELEASE}\n'

Get-HotFix | Select-Object HotFixID, InstalledOn

Продукты и затронутые версии

{
  "status": "affected",
  "version": "4.1.0",
  "versionType": "semver",
  "lessThanOrEqual": "4.1.2"
}

{
  "status": "affected",
  "version": "4.2.0",
  "versionType": "semver",
  "lessThanOrEqual": "4.2.1"
}

{
  "status": "affected",
  "version": "4.3.0",
  "versionType": "semver"
}

CVSS: оценки и векторы

Оценка CVSS отсутствует.

Источники и ссылки

{
  "cwes": [
    "cve",
    "ghsa",
    "nvd"
  ],
  "epss": {
    "source": "epss",
    "received_at": "2026-11-03T21:11:49.548638+00:00"
  },
  "title": {
    "source": "cve",
    "received_at": "2026-10-29T00:56:56.758210+00:00"
  },
  "scores": [],
  "status": {
    "source": "cve",
    "received_at": "2026-10-29T00:56:56.758210+00:00"
  },
  "affected": [
    "cve"
  ],
  "published": {
    "source": "cve",
    "received_at": "2026-10-29T00:56:56.758210+00:00"
  },
  "solutions": [],
  "percentile": {
    "source": "epss",
    "received_at": "2026-11-03T21:11:49.548638+00:00"
  },
  "references": [
    "cve",
    "ghsa",
    "nvd"
  ],
  "description": {
    "source": "cve",
    "received_at": "2026-10-29T00:56:56.758210+00:00"
  },
  "workarounds": [],
  "configurations": []
}

Хронология записи

1. Данные обновлены04.11.2026, 00:11
2. Данные обновлены03.11.2026, 00:11
3. Данные обновлены02.11.2026, 00:09
4. Данные обновлены31.10.2026, 11:57
5. Данные обновлены30.10.2026, 16:38
6. Данные обновлены29.10.2026, 03:56
7. Данные обновлены28.10.2026, 22:00
8. Опубликована28.10.2026, 20:29

Личная заметка и статус

Другие CVE того же продукта