# CVE-2026-93894: varnish: In Vinyl Cache before 9.0,2, workspace buffer overflow vulnerability was found in the .upper() and .lower() string ty...

CVE-2026-93894 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-93894, released September 18, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-93894
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0036
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 18, 2026

## Description

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.).

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | varnish Debian 13.5 (trixie) | 7.7.0-3+deb13u2 | [DEBIAN-CVE-2026-93894](https://patchblox.com/security/data/fix/linux/debian-cve-2026-93894.md) | Sep 18, 2026 |
| Linux | vinyl-cache Debian 14 | 9.0.1-4.1 | [DEBIAN-CVE-2026-93894](https://patchblox.com/security/data/fix/linux/debian-cve-2026-93894.md) | Sep 18, 2026 |

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Data as of 2026-11-09T07:25:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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