---
id: CVE-2026-93894
title: >-
  In Vinyl Cache before 9.0,2, workspace buffer overflow vulnerability was found
  in the .upper() and .lower() string type methods of VCL
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
  ass…
severity: low
cvss: 2.3
cvssVector: >-
  CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/AU:N/R:A/V:D/RE:L/U:Clear
cwe:
  - CWE-787
vendor: Vinyl-Cache
product: Vinyl Cache
affected:
  - vinyl_cache < 9.0.2
  - vinyl_cache < 90f5bacc14b2404e6cc349ba015f0f73b8515136
  - varnish_cache >= 9.0.0 < 9.0.4
  - varnish_cache < c5078ae575201b05ae8674a90ddb19ffe7f4b439
  - varnish_cache >= 6.3.0 <= 8.0.2
published: '2026-09-18'
updated: '2026-09-22'
sourceUpdated: '2026-09-22T20:00:03.713'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93894'
references:
  - url: 'https://vinyl-cache.org/security/VSV00020.html'
    label: cve@mitre.org
tags:
  - nvd
  - cve.org
epss: 0.00358
epssPercentile: 0.26807
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-19T13:26:42.982541Z'
cvssSource: cna
ingestedAt: '2026-09-18T20:51:25.792Z'
---

## Overview

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.).

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.