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.).
Advisories

No advisories yet.

Fixes

Solution

Update to unaffected Version


Workaround

replace the .upper() and .lower() VCL type method calls by their respective vmod_std counterparts: std.toupper() and std.tolower().

History

Fri, 18 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
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.).
Weaknesses CWE-787
References
Metrics cvssV4_0

{'score': 2.3, 'vector': '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'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-09-18T20:30:04.646Z

Reserved: 2026-09-18T20:30:04.310Z

Link: CVE-2026-93894

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-18T21:18:49.297

Modified: 2026-09-18T21:18:49.297

Link: CVE-2026-93894

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses