CVE-2026-115557
Python has added a denylist for known compromised certificates to the "ssl" module to ensure user safety even without certificate revocation
CVSS
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No CVSS
EPSS
0.5%
p45
KEV
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Exploit Today
13
0-100
Published: Oct 24, 2026 · Last modified: Oct 25, 2026 · CWE-299
Not enough EPSS history yet.
Python has added a denylist for known compromised certificates to the "ssl" module to ensure user safety even without certificate revocation configured. Known compromised certificates will automatically be rejected regardless of the SSLContext policy configuration.
- www.openwall.comhttp://www.openwall.com/lists/oss-security/2026/10/20/29
- emudhra.we-have-a-problem.comhttps://emudhra.we-have-a-problem.com/
- github.comhttps://github.com/python/cpython/commit/21a50891ab4be2e9955239e625ae2b40c6b1854d
- github.comhttps://github.com/python/cpython/commit/36cd295f32fc9ba19399e01abee91231440a41dd
- github.comhttps://github.com/python/cpython/commit/48d9b2712cd52206c7a5882d0fdca4863ed65e93
- github.comhttps://github.com/python/cpython/commit/7dd8b4736a1419750b94a388e6d158be15836fe6
- github.comhttps://github.com/python/cpython/commit/98f0e4ed349f370dc8a00366da1a9797e11c9ed5
- github.comhttps://github.com/python/cpython/commit/a17d9ef549008133eadf20689b1f4787902efe5b
- github.comhttps://github.com/python/cpython/commit/af52b41afa4330fb38583db553631baa2f122f90
- github.comhttps://github.com/python/cpython/commit/c7fd7edf7e0d122a3973cf676fae21b6aaa650a8
- github.comhttps://github.com/python/cpython/commit/e2a9dd97ef9571c710ac0afaa834c8879aebce78
- github.comhttps://github.com/python/cpython/commit/e4500d8a437ee5b988a5410cb9b59d177aa01370
- github.comhttps://github.com/python/cpython/commit/e4f63e65a93cf44c14274aa987e644b8c003625e
- github.comhttps://github.com/python/cpython/commit/e9bf2cf84eebf838a1edaa1c648c2b36345b99d3
- github.comhttps://github.com/python/cpython/issues/160040
- github.comhttps://github.com/python/cpython/pull/160042
- mail.python.orghttps://mail.python.org/archives/list/security-announce@python.org/thread/FNAJMZV6XQYLVPABNINDMF3VF66AYLW4/
- www.openwall.comhttp://www.openwall.com/lists/oss-security/2026/10/24/5
CVECVSSEPSSKEVRExploitTitleMod.
CVE-2026-1155707.4 HIG31.4%
——9Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 42.11.16, 43.8.1, 44.9.1, and 45.0.0-beta.6, Electron does not block compromised eMudhra intermediate certificates in Chromium networking, Node.js tls, Node.js https, or Node.js fetch. An attacker who holds a certificate issued through one of these intermediates and can intercept network traffic can impersonate a TLS server to an affected application. This issue is fixed in versions 42.11.16, 43.8.1, 44.9.1, and 45.0.0-beta.6.2dCVE-2026-1022214.4 MED29.8%
——9No cwe for this issue in Windows Secure Boot allows an authorized attacker to bypass a security feature locally.9dCVE-2026-944175.3 MED6.1%
——2When an application enables both OCSP and CRL revocation checking on one WOLFSSL_CTX or certificate manager, wolfSSL skips the CRL check for any peer certificate that carries no Authority Information Access OCSP URL, and accepts a certificate the loaded CRL lists as revoked. The soft-fail policy for a missing responder collapses the OCSP result onto success before the code decides whether the CRL fallback is still needed, so "no responder exists" becomes indistinguishable from "the responder answered good". Affected builds define both HAVE_OCSP and HAVE_CRL: --enable-ocsp --enable-crl directly, and implicitly --enable-all, --enable-distro, --enable-curl, --enable-nginx, --enable-haproxy, --enable-stunnel, --enable-lighty, --enable-wpas, --enable-strongswan, --enable-mosquitto, --enable-jni, --enable-openvpn and --enable-krb. An application is affected only if it calls both wolfSSL_CTX_EnableOCSP() (or wolfSSL_EnableOCSP() / wolfSSL_CertManagerEnableOCSP()) and wolfSSL_CTX_EnableCRL() (or the equivalents) with a CRL loaded; an application that uses OCSP stapling alone through wolfSSL_CTX_EnableOCSPStapling() is not affected, because that sets up a separate OCSP instance. The defect sits in ProcessPeerCerts() and is reachable over TLS 1.0 through TLS 1.3 and DTLS, both on a client verifying a server certificate and on a server verifying a client certificate under mutual or post-handshake authentication. When the skipped check falls on a chain certificate rather than the leaf, the unchecked intermediate is promoted into the certificate manager and stays a trusted signer for every later connection on that context, so an affected long-running process needs its WOLFSSL_CTX torn down and not only its library replaced. All wolfSSL versions from 5.9.2 and earlier are affected; on versions 5.9.1 and 5.9.2 the WOLFSSL_OCSP_CHECKALL configuration fails closed with OCSP_NEED_URL, which leaves wolfSSL_CTX_EnableOCSP() without CHECKALL as the exposed configuration on 5.9.2.26dCVE-2026-735816.5 MED5.0%
——2Improper Check for Certificate Revocation vulnerability in Apache Tomcat. Both the OpenSSL and OpenSSL-FFM TLS implementations ignore CRLs when certificate uses a keystore.
This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.58, from 9.0.0-M1 through 9.0.121.
The following versions were EOL at the time the CVE was created but are
known to be affected: from 8.5.0 through 8.5.100. Other unsupported versions may also be affected.
Users are recommended to upgrade to version 11.0.26, 10.1.59, 9.0.122, which fixes the issue.32dCVE-2026-936024.4 MED9.8%
——3rustls-webpki versions before 0.103.10 and 0.104.0-alpha.5 contain faulty CRL authority-matching logic that compares only the first distributionPoint against each CRL's IssuingDistributionPoint, ignoring additional distributionPoints. Attackers with a compromised trusted issuing authority can present revoked certificates that pass revocation checks under UnknownStatusPolicy::Allow, or cause incorrect errors under the default deny policy.33dCVE-2026-934935.9 MED12.2%
——4A flaw was found in Netty's `netty-handler-ssl-ocsp` component. A remote attacker can exploit this vulnerability by providing an Online Certificate Status Protocol (OCSP) response that omits the optional `nextUpdate` field. This omission causes the OCSP validation to be silently skipped, leading to applications proceeding with an unvalidated certificate. This can result in a bypass of security controls where certificate validation is expected.37d