CVE-2025-47905
No exploitation reported by the sources we read.
- Published2025-05-13
- Fixed in6.6.2
- WeaknessCWE-444
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
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.
Timeline
dates in UTC- 2025-05-1322:15CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-23 21:37 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2025-47905?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2025-47905?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
OSV| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 6.6 | < 6.6.2 | 6.6.2 | OSV |
| 7.0+ | ≥ 7.0.0 | no fix published | OSV |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Distribution builds and vendor advisories
Packages from OSV.dev and products from the vendors' CSAF advisories.
version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.
Packages
- varnishAlmaLinux:10all versions · fixed in 7.6.1-2.el10_0.1and 2 other packages
- varnishAlmaLinux:9all versions · fixed in 6.6.2-6.el9_6.1and 2 other packages
- varnishAlmaLinux:8all versions · fixed in 6.0.13-1.module_el8.10.0+4003+9759c3c1.1and 2 other packages
- varnish-modulesAlmaLinux:8all versions · fixed in 0.15.0-6.module_el8.9.0+3826+307eaba4
Vendor advisories
varnish: request smuggling attacks
Red Hat Security Advisory: varnish security update
Red Hat Security Advisory: varnish:6 security update
Red Hat Security Advisory: varnish security update
Red Hat Security Advisory: varnish security update
Red Hat Security Advisory: varnish security update
5 more advisories
Fix
- Update varnish to 6.6.2
- Vendor fix Red Hat Product Security RHSA-2025:8550 · 13 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
- Workaround from the vendor Red Hat Product Security RHSA-2025:8550 · 13 productsCurrently, no mitigation is available for this vulnerability.
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
- Published
- 2025-05-13
- Last Modified
- 2026-06-17
- NVD status
- Deferred
Frequently asked questions
What is CVE-2025-47905?
Is CVE-2025-47905 actively exploited?
What is the CVSS score for CVE-2025-47905?
Running Varnish Cache? Hear about its next vulnerability
Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».
No credit card required · No monthly cap on website lookups · 250 API requests/month
Go further
- Following what attackers exploit right now? The CISA KEV additions of the month, with their patch deadlines.
- Running this software? Vulnerability monitoring alerts you to new vulnerabilities in your products.
Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.