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io.netty:netty-handler-ssl-ocsp

Open actionable advisories and recorded vendor fixes. This public package view has no inventory attached and cannot establish whether your deployment is affected. A vendor fix never resolves your finding; verify your installed version and the source guidance.

Open advisories

3 actionable advisories, newest first. Withdrawn advisories and news are excluded. Coverage is partial.

  1. High, CVSS 7.4MavenPublished

    Netty: TOCTOU in OcspServerCertificateValidator

    CVE-2026-56822 · GHSA-wc96-39fc-566f

    Affected
    • Maven io.netty:netty-handler-ssl-ocsp >= 4.2.0.Final, < 4.2.16.Final; < 4.1.136.Final
    Fixed in
    4.2.16.Final4.1.136.Final· Vendor fix available
    Issue
    Netty's OcspServerCertificateValidator forwards the SslHandshakeCompletionEvent before the asynchronous OCSP validation completes. This allows the client's downstream handlers to send sensitive application data (e.g., HTTP requests) to a revoked server before the channel is closed by the OCSP check. Details In io.netty.handler.ssl.ocsp.OcspServerCertificateValidator#userEventTriggered, when an SslHandshakeCompletionEvent is received, the validator immediately calls ctx.fireUserEventTriggered(evt). It then initiates an asynchronous OCSP query using OcspClient.query. Because the handshake completion event is forwarded immediately, downstream handlers in the client's pipeline are notified that the TLS handshake is successful. They may then begin reading and processing incoming application data or sending outgoing data. If the OCSP response later indicates the server's certificate is REVOKED, the validator closes the channel, but by this time, the client may have already leaked…

    Recommended action: Upgrade to 4.2.16.Final or 4.1.136.Final by release line, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.

    Sources:github.comSource checked Evidence →
  2. High, CVSS 7.4MavenPublished

    Netty: Out-of-date OCSP Responses Accepted by OcspServerCertificateValidator

    CVE-2026-56821 · GHSA-g7hg-vrcf-mvmr

    Affected
    • Maven io.netty:netty-handler-ssl-ocsp >= 4.2.0.Final, < 4.2.16.Final; < 4.1.136.Final
    Fixed in
    4.2.16.Final4.1.136.Final· Vendor fix available
    Issue
    OcspServerCertificateValidator flags an out-of-date OCSP response but does not stop processing it, so an expired GOOD response is still reported as VALID, letting an on-path attacker replay a stale GOOD response to bypass revocation of a since-revoked certificate. Details In io.netty.handler.ssl.ocsp.OcspServerCertificateValidator#userEventTriggered the freshness check has no return, so execution falls through and a VALID OcspValidationEvent is still fired: Nonce validation is optional and off by default, so freshness is the only replay defense — and it is not enforced. Additionally getNextUpdate() may be null, making current.before(null) throw NullPointerException. https://datatracker.ietf.org/doc/html/rfc6960#section-3.2 PoC Add the test below to io.netty.handler.ssl.ocsp.OcspServerCertificateValidatorTest Impact Certificate revocation bypass via replay of an expired OCSP response. Any application using OcspServerCertificateValidator is affected; a revoked certificate can…

    Recommended action: Upgrade to 4.2.16.Final or 4.1.136.Final by release line, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.

    Sources:github.comSource checked Evidence →
  3. High, CVSS 7.4MavenPublished

    Netty: Missing CertificateID Validation in OCSP Response Allows Replay Attacks

    CVE-2026-56820 · GHSA-272m-gcwp-mpwg

    Affected
    • Maven io.netty:netty-handler-ssl-ocsp >= 4.2.0.Final, < 4.2.16.Final; < 4.1.136.Final
    Fixed in
    4.2.16.Final4.1.136.Final· Vendor fix available
    Issue
    Netty's OcspClient does not validate that the CertificateID in an OCSP response matches the requested CertificateID. A bad actor can replay a GOOD status response issued for an unrelated certificate (by the same CA) to bypass revocation checks for any certificate. Details io.netty.handler.ssl.ocsp.OcspClient#validateResponse fails to assert that the CertificateID within the returned BasicOCSPResp matches the original certificate being validated. When OcspClient.query(...) executes, it builds an OCSP request using the victim certificate's serial number and issuer hash. It then sends this request and receives a response. While the client verifies the signature of the response against the trusted issuer (or a valid responder chain), it never checks the CertificateID inside the response payload. A bad actor who has access to any other valid, non-revoked certificate issued by the same CA can obtain a legitimately signed OCSP response indicating that the unrelated certificate is…

    Recommended action: Upgrade to 4.2.16.Final or 4.1.136.Final by release line, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.

    Sources:github.comSource checked Evidence →