Quick answers
- Is This vulnerability exploited in the wild?
- No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.
- How severe is This vulnerability?
- Medium severity, with a CVSS score of 5.3, published 1 August 2026.
- Which products and versions are affected?
- Guzzle < 7.15.1; guzzlehttp/guzzle (Packagist) < 7.15.1.
- Is there a fix for This vulnerability?
- A patch was published on 2026-08-04: Advisory updated to reflect patch availability in 7.15.1 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is This vulnerability attacked?
- It is attacked over the network, in a software library.
- Am I affected?
- Check whether you run Guzzle or guzzlehttp/guzzle (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A denial of service vulnerability exists in guzzlehttp/guzzle's CookieJar implementation (CWE-770, CWE-1325). The library fails to impose limits on the number of 'Set-Cookie' header fields or the size of individual cookies received in an HTTP response. An attacker-controlled server can return a large volume of cookie data, leading to excessive memory consumption. Furthermore, Guzzle may generate oversized 'Cookie' headers in subsequent requests that exceed the limits of downstream handlers, proxies, or destination servers, causing request failures. The issue is resolved in version 7.15.1, which introduces an 8,190-byte limit per cookie and a maximum of 50 cookies per response.
Affected products
- guzzlehttp guzzle < 7.15.1
Timeline
- 2026-07-18: advisory: Original GHSA-f283-ghqc-fg79 published by maintainers
- 2026-08-01: disclosed: CVE-2026-67353 published to NVD
- 2026-08-04: patched: Advisory updated to reflect patch availability in 7.15.1