CVE-2026-67355
Guzzle <7.15.1 exposes host-only cookies to child hosts, risking session/token disclosure.
Is CVE-2026-67355 being exploited?
Not confirmed. CVE-2026-67355 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.23% probability of exploitation in the next 30 days.
How severe is CVE-2026-67355?
CVE-2026-67355 is rated High. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-67355?
Yes. A fix has been recorded for CVE-2026-67355. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-67355 affect?
CVE-2026-67355 affects guzzlehttp/guzzle < 7.15.1, PHP applications using shared cookie jars across domains. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-67355?
Upgrade to guzzle 7.15.1 and avoid sharing cookie jars across trust boundaries.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Attackers controlling child hosts can read host-only cookies (session IDs/auth tokens) when cookie jars are reused, enabling session hijack or token theft.
Immediate action required
- affected< 7.15.1
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.