TI-2026-63202 Aliases CVE-2026-93894 GHSA-pfj3-384h-g8q8

Out-of-bounds write in Vinyl-Cache Vinyl Cache

LOW 12CWE-787Published 2026-09-18 · Updated 2026-09-19

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: High
Attack requirements: Present
Impact type: —
Confidentiality · integrity · availability: None · None · Low
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

In Vinyl Cache before 9.0,2, workspace buffer overflow vulnerability was found in the .upper() and .lower() string type methods of VCL. This can be used as a remote denial of service (DoS) vector to make the child process segfault or assert, and then restart. Effectively exploiting this vulnerability requires prior knowledge about the VCL in use and the ability to craft a request that contains a string that is long enough to fill the remaining workspace at the call site while staying under the different request size limits (http_req_size, http_req_hdr_len, etc.).

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00358 29th percentileScored 2026-11-07

Fix Fixed Vinyl Cache (Vinyl-Cache): 9.0.2Varnish Cache (Varnish-Software): 9.0.4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Vinyl-Cache	Vinyl Cache	before 9.0.2	9.0.2	Patch available	CNA
varnish-software	Varnish Cache	9.0.0 to before 9.0.4; 6.3.0 – 8.0.2	9.0.4	Patch available	CNA

Vinyl Cache VendorVinyl-Cache Affected before 9.0.2 Fixed in 9.0.2 Patch available CNA
Varnish Cache Vendorvarnish-software Affected 9.0.0 to before 9.0.4; 6.3.0 – 8.0.2 Fixed in 9.0.4 Patch available CNA

Remediation

Fix · CNA Vinyl Cache (Vinyl-Cache) Fixed in 9.0.2
Fix · CNA Varnish Cache (Varnish-Software) Fixed in 9.0.4

Timeline

2026-10-02 Threatist record created from CVE-2026-93894
2026-10-03 Alias added: GHSA-pfj3-384h-g8q8

References

Other 1

https://vinyl-cache.org/security/VSV00020.html

TI-2026-26733 Varnish Cache before 8.0.1 and Varnish Enterprise before 6.0.16r12, in certain unchecked… CVSS 3.1CRITICAL 9.8
TI-2026-29164 Varnish Cache 9 before 9.0.1 allows a "workspace overflow" denial of service (daemon… CVSS 3.1HIGH 7.5
TI-2026-29162 Varnish Cache 9 before 9.0.1 and Varnish Enterprise before 6.0.16r11 allows a "workspace… CVSS 3.1HIGH 7.5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences