What is CVE-2026-105236?

CVE-2026-105236 is TLS 1.2 session resumption in ssl crosses SNI virtual-host client-certificate trust boundaries. The supplied enrichment data classifies it as Cryptography mapped to CWE-295 CWE-295.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Active exploitation is not confirmed from current sources for CVE-2026-105236. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-105236 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

A public PoC is not confirmed from current sources for CVE-2026-105236. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-105236 using CVSS 6.3, EPSS 0%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Prioritize based on EPSS, PoC availability, and external exposure. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

mediumCryptography

CVE-2026-105236

CVE-2026-105236 — TLS 1.2 session resumption in ssl crosses SNI virtual-host client-certificate trust boundaries

Improper Certificate Validation vulnerability in the ssl application in Erlang/OTP allows a client that holds a certificate trusted by one SNI virtual host to authenticate to a second SNI virtual host on the same listener by resuming its TLS 1.2 session there. A server that serves several SNI names from one listen socket through sni_fun or sni_hosts keeps one pre-TLS 1.3 session cache per listener and does not bind a cached session to the SNI name or client trust policy that established it. When an SNI option set switches to verify_peer without naming reuse_sessions, ssl_config:update_options/3 inherits the base listener's reuse_sessions value of true, so the default that disables reuse for client-authenticating servers does not apply. On an abbreviated handshake ssl_session:is_resumable/4 checks only that the cached session uses one of the current server certificates and carries some peer certificate, and never revalidates that certificate against the CA selected for the requested name. The names must share a server certificate, which is common with wildcard or multi-SAN certificates. TLS 1.3 does not use this cache and is not affected. This issue affects OTP from OTP 18.0 before OTP 27.3.4.19, OTP 28.5.0.8, and OTP 29.1.2, corresponding to ssl from 7.0 before 11.2.12.14, 11.6.0.7, and 11.7.8.

Published Oct 14, 2026Updated Oct 14, 2026Sources: NVD, Erlang (CNA), GitHub, SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

ahead of 0% of scored CVEs

Affects

Erlang

3 products listed

CVSS base

6.3

medium

Remediation

The vendor's own words where we have them.

Upgrade OTP to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Prioritize based on EPSS, PoC availability, and external exposure.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
Erlang	OTP	18.0	Vulnerable
Erlang	OTP	7.0	Vulnerable
Erlang	OTP	4fe38c4b8b2c8024afb60990e598ff823743fd54	Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Scope

Attack Complexity

Low

Attack Vector

Network

Privileges Req

None

User Interaction

None

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
6.3	CVSS 4.0	medium	—	—	Erlang (CNA)

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-295 · Improper Certificate Validation

Bypass Protection Mechanism
Gain Privileges or Assume Identity::

Mitigation: Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.

Weakness & attack patterns

CWE-295

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

CAPEC-475 · Signature Spoofing by Improper ValidationCAPEC-459 · Creating a Rogue Certification Authority Certificate

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Search application, proxy, and WAF logs for requests touching /OTP, /3, /4.
Prioritize edge telemetry for network-reachable OTP.

web/proxy/WAF logsapplication logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 6.3 (AV:N)
Oct 14, 2026 · NVD
Initial · CVE published
Oct 14, 2026 · NVD
CVE published by MITRE.
Oct 14, 2026 · SOCRadar CTI

References

9 on the record

cna.erlef.org/cves/CVE-2026-105236.html
Vendor Advisory, Mitre, NIST
github.com/erlang/otp/commit/0c20f3683b3c81fd30b46047195be9b3d2c69d76
Exploit, Third Party Advisory, Mitre, NIST
github.com/erlang/otp/commit/10ee925d0fee8413f1170cc21bfcf123c8d22454
Exploit, Third Party Advisory, Mitre, NIST
github.com/erlang/otp/commit/4d76adbf39d547a931048544df09c3c087e56618
Exploit, Third Party Advisory, Mitre, NIST
github.com/erlang/otp/commit/4fe38c4b8b2c8024afb60990e598ff823743fd54
Exploit, Third Party Advisory, Mitre, NIST
github.com/erlang/otp/security/advisories/GHSA-2g23-cgjh-34gq
Exploit, Third Party Advisory, Mitre, NIST
osv.dev/vulnerability/EEF-CVE-2026-105236
Vendor Advisory, Mitre, NIST
www.erlang.org/doc/system/versions.html#order-of-versions
Vendor Advisory

Elsewhere on this site

Erlangevery CVE for this vendor
Cryptographysame class
CWE-295other pages naming this weakness

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 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 record1

What should defenders know first?

CVE-2026-105236 is TLS 1.2 session resumption in ssl crosses SNI virtual-host client-certificate trust boundaries, a medium vulnerability affecting OTP from Erlang. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-105236. Public exploit evidence is: A public PoC is not confirmed from current sources for CVE-2026-105236. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 6.3 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.