Vulnerability in Varnish-software Varnish Cache

CVE-2025-47905

Varnish Cache before 7.6.3 and 7.7 before 7.7.1, and Varnish Enterprise before 6.0.13r14, allow client-side desync via HTTP/1 requests, because the product incorrectly permits CRLF to be skipped to delimit chunk boundaries.

Vulnerability class: HTTP Request Smuggling

EPSS: 0.003 (52.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-47905?
CVE-2025-47905 is a medium-severity vulnerability in Varnish-software Varnish Cache, classified under Inconsistent Interpretation of HTTP Requests (HTTP Request/Response Smuggling). CVSS score: 5.4/10. Published 2025-05-13.
How severe is CVE-2025-47905?
Medium severity. CVSS v3 base score is 5.4 out of 10.
Is CVE-2025-47905 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.