CVE-2026-27448

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Source
https://cve.org/CVERecord?id=CVE-2026-27448
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-27448.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-27448
Aliases
Downstream
Related
Published
2026-03-17T23:24:30.661Z
Modified
2026-03-20T17:44:20.752002Z
Severity
  • 1.7 (Low) CVSS_V4 - CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U CVSS Calculator
Summary
pyOpenSSL allows TLS connection bypass via unhandled callback exception in set_tlsext_servername_callback
Details

pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 0.14.0 and prior to version 26.0.0, if a user provided callback to set_tlsext_servername_callback raised an unhandled exception, this would result in a connection being accepted. If a user was relying on this callback for any security-sensitive behavior, this could allow bypassing it. Starting in version 26.0.0, unhandled exceptions now result in rejecting the connection.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27448.json",
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-636"
    ]
}
References

Affected packages

Git / github.com/pyca/pyopenssl

Affected ranges

Type
GIT
Repo
https://github.com/pyca/pyopenssl
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
358cbf29c4e364c59930e53a270116249581eaa3

Affected versions

0.*
0.14
0.14a2
0.14a3
0.14a4
0.15
0.15.1
16.*
16.0.0
16.1.0
16.2.0
17.*
17.1.0
17.2.0
17.3.0
17.4.0
17.5.0
18.*
18.0.0
19.*
19.0.0
19.1.0
20.*
20.0.0
20.0.1
21.*
21.0.0
22.*
22.0.0
22.1.0
23.*
23.0.0
23.1.0
23.2.0
23.3.0
24.*
24.0.0
24.1.0
24.2.0
24.2.1
24.3.0
25.*
25.0.0
25.1.0
25.2.0
25.3.0
v0.*
v0.14a1

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-27448.json"