CVE-2026-85088
published 2026-10-02CVE-2026-85088: Improper Validation of Certificate with Host Mismatch in the C++ and D libraries of Apache Thrift. Both libraries install a default access manager for client…
PriorityP338medium6.9CVSS 4.0
AVNACHATPPRNUINVCHVIHVANSCNSINSANEUCRXIRXARXMAVXMACXMATXMPRXMUIXMVCXMVIXMVAXMSCXMSIXMSAXSXAUXRXVXREXUX
EPSS
0.17%
6.3th percentile
Improper Validation of Certificate with Host Mismatch in the C++ and D libraries of Apache Thrift.
Both libraries install a default access manager for client sockets — TSSLSocketFactory does so in C++, and the accessManager property does so in D — which compares the peer certificate against the host
name that was connected to. That comparison walks the subjectAltName dNSName entries first and consults the certificate Common Name afterwards. A name that does not match yields a "skip" result rather than
a rejection, so a certificate whose subjectAltName entries are all present and all non-matching falls through to the Common Name, which can then satisfy the check.
RFC 6125 section 6.4.4, and RFC 9525 section 2, require that the Common Name is not consulted when a dNSName subjectAltName is present. A certificate carrying subjectAltName entries for one name and a
Common Name for another is therefore accepted for a connection to the second name.
Exploitation requires an attacker positioned on the network path who holds a certificate that chains to a certificate authority in the client's trust store and whose Common Name matches the connected host
name. Public certificate authorities have not issued on Common Name alone for many years, so this is principally a concern for deployments using a private or enterprise public-key infrastructure.
This issue affects the C++ library of Apache Thrift from 0.7.0 through 0.24.0 and the D library from 0.9.0 through 0.24.0. Users should upgrade to 0.25.0.
Affected
2 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| apache | thrift | — | — |
| apache_software_foundation | apache_thrift | < 0.25.0 | 0.25.0 |
CVSS provenance
nvdv4.06.9MEDIUMCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
vendor_redhat6.9MEDIUM
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Red Hat
thrift: thrift: Man-in-the-middle attacks via improper certificate validation
vendor_redhat·2026-10-02·CVSS 6.9
CVE-2026-85088 [MEDIUM] CWE-295 thrift: thrift: Man-in-the-middle attacks via improper certificate validation
thrift: thrift: Man-in-the-middle attacks via improper certificate validation
A flaw was found in Apache Thrift. During Transport Layer Security (TLS) certificate validation, the client libraries improperly evaluate the certificate's Common Name (CN) when subject alternative name (SAN) entries do not match the target host. A network-positioned attacker possessing a trusted certificate matching the host's Common Name can exploit this vulnerability to impersonate the legitimate server. Successful exploitation allows the attacker to intercept or tamper with encrypted communications.
Package: thrift (Red Hat Ceph Storage 7) - Affected
Package: thrift (Red Hat Ceph Storage 8) - Affected
Package: thrift (Red Hat Ceph Storage 9) - Affected
Package: thrift (Red Hat Enterprise Linux AI (RHEL A
GHSA
Improper Validation of Certificate with Host Mismatch in the C++ and D libraries of Apache Thrift.
ghsa_unreviewed·2026-10-02
CVE-2026-85088 [MEDIUM] CWE-295 Improper Validation of Certificate with Host Mismatch in the C++ and D libraries of Apache Thrift.
Improper Validation of Certificate with Host Mismatch in the C++ and D libraries of Apache Thrift.
Both libraries install a default access manager for client sockets — TSSLSocketFactory does so in C++, and the accessManager property does so in D — which compares the peer certificate against the host
name that was connected to. That comparison walks the subjectAltName dNSName entries first and consults the certificate Common Name afterwards. A name that does not match yields a "skip" result rather than
a rejection, so a certificate whose subjectAltName entries are all present and all non-matching falls through to the Common Name, which can then satisfy the check.
RFC 6125 section 6.4.4, and RFC 9525 section 2, require that the Common Name is not consulted when a dNSName subjectAltName
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-85088 thrift: thrift: Man-in-the-middle attacks via improper certificate validation [epel-all]
bugzilla·2026-10-22·CVSS 6.9
CVE-2026-85088 [MEDIUM] CVE-2026-85088 thrift: thrift: Man-in-the-middle attacks via improper certificate validation [epel-all]
CVE-2026-85088 thrift: thrift: Man-in-the-middle attacks via improper certificate validation [epel-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Improper Validation of Certificate with Host Mismatch in the C++ and D libraries of Apache Thrift.
Both libraries install a default access manager for client sockets — TSSLSocketFactory does so in C++, and the accessManager property does so in D — which compares the peer certificate against the host
name that was connected to. That comparison walks the subjectAltName dNSName entries first and consults the certificate Common Name afterwards. A name that does not m
Bugzilla
CVE-2026-85088 thrift: thrift: Man-in-the-middle attacks via improper certificate validation [fedora-all]
bugzilla·2026-10-22·CVSS 6.9
CVE-2026-85088 [MEDIUM] CVE-2026-85088 thrift: thrift: Man-in-the-middle attacks via improper certificate validation [fedora-all]
CVE-2026-85088 thrift: thrift: Man-in-the-middle attacks via improper certificate validation [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Improper Validation of Certificate with Host Mismatch in the C++ and D libraries of Apache Thrift.
Both libraries install a default access manager for client sockets — TSSLSocketFactory does so in C++, and the accessManager property does so in D — which compares the peer certificate against the host
name that was connected to. That comparison walks the subjectAltName dNSName entries first and consults the certificate Common Name afterwards. A name that does not
Bugzilla
CVE-2026-85088 thrift: thrift: Man-in-the-middle attacks via improper certificate validation
bugzilla·2026-10-02·CVSS 6.9
CVE-2026-85088 [MEDIUM] CVE-2026-85088 thrift: thrift: Man-in-the-middle attacks via improper certificate validation
CVE-2026-85088 thrift: thrift: Man-in-the-middle attacks via improper certificate validation
Improper Validation of Certificate with Host Mismatch in the C++ and D libraries of Apache Thrift.
Both libraries install a default access manager for client sockets — TSSLSocketFactory does so in C++, and the accessManager property does so in D — which compares the peer certificate against the host
name that was connected to. That comparison walks the subjectAltName dNSName entries first and consults the certificate Common Name afterwards. A name that does not match yields a "skip" result rather than
a rejection, so a certificate whose subjectAltName entries are all present and all non-matching falls through to the Common Name, which can then satisfy the check.
RFC 6125 section 6.4.4, and R
2026-10-02
Published