CVE-2026-6092

TLS confidentiality downgrade via failed session resumption

Published Jun 25, 2026 · Updated Jun 25, 2026

Algorithm downgrade in wolfSSL 5.2.0 through 5.9.1 allows man-in-the-middle attackers to weaken TLS 1.2 record confidentiality. In DoClientHello, a failed session-cache lookup follows the non-resumption path but still runs ETM response and disable logic before cipher specifications are populated, silently disabling negotiated Encrypt-then-MAC. The condition requires HAVE_ENCRYPT_THEN_MAC, failed TLS 1.2 session resumption, adjacent access, and low privileges; no integrity or availability impact is reported.

CVSS severity2.1
Low
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Algorithm downgrade in wolfSSL 5.2.0 through 5.9.1 allows man-in-the-middle attackers to weaken TLS 1.2 record confidentiality. In DoClientHello, a failed session-cache lookup follows the non-resumption path but still runs ETM response and disable logic before cipher specifications are populated, silently disabling negotiated Encrypt-then-MAC. The condition requires HAVE_ENCRYPT_THEN_MAC, failed TLS 1.2 session resumption, adjacent access, and low privileges; no integrity or availability impact is reported.

The record

CVE
CVE-2026-6092
Published
Jun 25, 2026
Updated
Jun 25, 2026
Vendor
wolfSSL
Product
wolfSSL
Classifications
CWE-757, CAPEC-620, T1557
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.2.0 <=5.9.1

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

wolfSSL · wolfSSLversion=5.2.0 <=5.9.1

Published CVSS scores

5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
2.1wolfSSL Inc.CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-757Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')
CAPEC-620Drop Encryption Level
T1557Adversary-in-the-Middle

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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