CVE-2026-13697

undici vulnerable to cross-user information disclosure and parse-time crash via degenerate private cache directives

Published Jul 29, 2026 CVSS 3.1 · 7.4 High EPSS < 1% KEV · Not listed
Description
undici's cache interceptor mishandles malformed Cache-Control private directives. In undici 7.0.0 up to before 7.29.0 and 8.0.0 up to before 8.9.0, a response carrying a degenerate qualified private directive, such as private set to an empty value, can be stored in the default shared cache and later served to a different caller with the same cache key, disclosing private response bodies and headers including Set-Cookie. Separately, a Cache-Control header that combines an unqualified private directive with a qualified one triggers an uncaught TypeError in the cache-control parser, which rejects the request and, depending on the consumer's error handling, can terminate the process. Both issues affect applications using the cache interceptor in shared mode, including the default configuration. The issues are fixed in undici 7.29.0 and 8.9.0.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-4cwx-7wf7-3272 undici vulnerable to cross-user information disclosure and parse-time crash via degenerate private cache directives
History
Type Values Removed Values Added
First Time appeared Redhat
Redhat hummingbird
Weaknesses CWE-524
CPEs cpe:/a:redhat:hummingbird:1
Vendors & Products Redhat
Redhat hummingbird
References
Metrics threat_severity

None

threat_severity

Important

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Undici
Undici undici
Vendors & Products Undici
Undici undici
Type Values Removed Values Added
Description undici's cache interceptor mishandles malformed Cache-Control private directives. In undici 7.0.0 up to before 7.29.0 and 8.0.0 up to before 8.9.0, a response carrying a degenerate qualified private directive, such as private set to an empty value, can be stored in the default shared cache and later served to a different caller with the same cache key, disclosing private response bodies and headers including Set-Cookie. Separately, a Cache-Control header that combines an unqualified private directive with a qualified one triggers an uncaught TypeError in the cache-control parser, which rejects the request and, depending on the consumer's error handling, can terminate the process. Both issues affect applications using the cache interceptor in shared mode, including the default configuration. The issues are fixed in undici 7.29.0 and 8.9.0.
Title undici vulnerable to cross-user information disclosure and parse-time crash via degenerate private cache directives
Weaknesses CWE-200
CWE-248
CWE-525
References
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H'}

Sources

Status
PUBLISHED
Assigner
openjs
Published
Updated
Jul 29, 2026, 5:53 PM
Reserved
Jun 29, 2026, 11:30 AM
Status
Analyzed
Published
Jul 29, 2026, 5:16 PM
Modified
Aug 4, 2026, 2:17 PM
Severity
Important
Public date
Jul 29, 2026, 4:32 PM