Service interruption via unbounded response cookies
Published Aug 1, 2026 · Updated Aug 1, 2026
Denial of service in Guzzle before 7.15.1 allows remote attackers to interrupt applications via oversized response cookies. The built-in CookieJar stores unlimited Set-Cookie fields and later copies every matching cookie into one unbounded Cookie header. Exploitation requires enabled cookie support, an attacker-controlled response, and retention or reuse of the jar; the demonstrated consequence is increased resource use or failed requests.
Summary
What happened
Denial of service in Guzzle before 7.15.1 allows remote attackers to interrupt applications via oversized response cookies. The built-in CookieJar stores unlimited Set-Cookie fields and later copies every matching cookie into one unbounded Cookie header. Exploitation requires enabled cookie support, an attacker-controlled response, and retention or reuse of the jar; the demonstrated consequence is increased resource use or failed requests.
The record
- CVE
- CVE-2026-67353
- Published
- Aug 1, 2026
- Updated
- Aug 1, 2026
- Vendor
- Guzzle
- Product
- Guzzle
- Classifications
- CWE-1325, CWE-770, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 1, 2026CVE publishedPublication date reported by the CVE source.
- Aug 1, 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.
- Affected versionversion=0 <7.15.1
What conditions does exploitation require?
What is affected?
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.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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