CVE-2026-85088 — Apache Thrift, Apache Thrift: The C++ and D clients fall back to the certificate Common Name when subjectAltName entries are present but do not match
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+2
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Apache Software Foundation Thrift).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (cryptography), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Apache Software Foundation | Thrift | < 0.25.0 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 6.9 | CVSS 4.0 | Medium | — | — | security@apache.org via NIST National Vulnerability Database |
| 6.9 | CVSS 4.0 | Medium | — | — | apache via CVE Program (cve.org) e CISA ADP |
CVSS: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 (score shown at the top: security@apache.org) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Check TLS negotiations and unexpected certificates in the component’s traffic.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · apache software foundation/apache thrift
- SSVC assessment updated
- Record published
- CVSS changed · 6.9
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
2 on the record
Elsewhere on this site
Related CVEs (same products)
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Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-85088 is "Apache Thrift, Apache Thrift: The C++ and D clients fall back to the certificate Common Name when subjectAltName entries are present but do not match", rated Medium. It affects Thrift (Apache Software Foundation); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.9 describes technical severity. EPSS 0.22% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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