An issue was discovered in Varnish Cache before 6.0.5 LTS, 6.1.x and 6.2.x before 6.2.2…
Priority LOW 36CWE-212Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Partial Red Hat: 1 fixed, 1 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
An issue was discovered in Varnish Cache before 6.0.5 LTS, 6.1.x and 6.2.x before 6.2.2, and 6.3.x before 6.3.1. It does not clear a pointer between the handling of one client request and the next request within the same connection. This sometimes causes information to be disclosed from the connection workspace, such as data structures associated with previous requests within this connection or VCL-related temporary headers.
Why it matters now
EPSS 0.0179 78th percentileScored 2026-11-07
Fix Partial Red Hat: 1 advisoryRed Hat: 1 fixed, 1 without a fix
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:varnish-cache:varnish_cache:*:*:*:*:-:*:*:* | 6.1.0 to before 6.2.2; 6.3.0 to before 6.3.1 | Vulnerable | Varnish-cache |
| cpe:2.3:a:varnish-software:varnish_cache:*:*:*:*:lts:*:*:* | 6.0.0 to before 6.0.5 | Vulnerable | varnish-software |
| cpe:2.3:a:opensuse:backports_sle:15.0:sp1:*:*:*:*:*:* | 15.0 sp1 | Vulnerable | openSUSE |
| cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:* | 15.1 | Vulnerable | openSUSE |
- cpe:2.3:a:varnish-cache:varnish_cache:*:*:*:*:-:*:*:* Versions 6.1.0 to before 6.2.2; 6.3.0 to before 6.3.1 Vulnerable ·Varnish-cache
- cpe:2.3:a:varnish-software:varnish_cache:*:*:*:*:lts:*:*:* Versions 6.0.0 to before 6.0.5 Vulnerable ·varnish-software
- cpe:2.3:a:opensuse:backports_sle:15.0:sp1:*:*:*:*:*:* Versions 15.0 sp1 Vulnerable ·openSUSE
- cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:* Versions 15.1 Vulnerable ·openSUSE
Remediation
Red Hat 1 advisory
- RHSA-2020:4756 Released 2020-11-04 · Red Hat rating Moderatevarnish:6 security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 8) varnish-6.0.6-2.module+el8.3.0+6843+b3b42fcc.aarch64::varnish:6, varnish-6.0.6-2.module+el8.3.0+6843+b3b42fcc.ppc64le::varnish:6, varnish-6.0.6-2.module+el8.3.0+6843+b3b42fcc.s390x::varnish:6 +15
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Software Collections | Affected | No fix yet |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2020:4756 |
Timeline
- 2026-10-02 Threatist record created from CVE-2019-20637
- 2026-10-03 Alias added: GHSA-h2vv-cmjp-m2w5
References
Sources
- CVE-2019-20637 · CVE Program
- CVE-2019-20637 · NVD
- FIRST EPSS
- GHSA-h2vv-cmjp-m2w5 · GitHub Advisory Database · CC BY 4.0
- CVE-2019-20637 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences