2.3

CVE-2026-93894: varnish-software varnish_cache Out-of-bounds Write

CVSS: 2.3v4.0LowDeferred
AliasesUBUNTU-CVE-2026-93894DEBIAN-CVE-2026-93894
Published 18-09-2026Last modified 19-09-2026
Open JSON

Vulnerability summary

CVE-2026-93894 is a low (CVSS 2.3) Out-of-bounds Write vulnerability in varnish-software varnish_cache. EPSS estimates a 0.36% chance of exploitation in the next 30 days, higher than 28% of scored vulnerabilities.

Overall risk
9/100
0100
Minimal · default modelHow is this calculated?
CVSS score
2.3/10
010
Low · v4.0 (CVE.org)
EPSS score
0.36%
0%100%
Low · +0.11 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 18-09-2026
    PublishedVulnerability first disclosed.
  2. 19-09-2026
    Last modifiedVulnerability information updated.

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.).

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.36%

Chance of exploitation in the next 30 days

Percentile

28%

Versus all other CVEs

30-day change

+0.11 pp

From 0.25% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.36%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian2 products
  • varnishAll versions (No fix recorded)
  • vinyl-cacheAll versions (No fix recorded)
Ubuntu2 products
  • varnishAll versions (No fix recorded)
  • vinyl-cacheAll versions (No fix recorded)
Varnish-software1 product
  • varnish_cache≥ 9.0.0, < 9.0.4 | < c5078ae575201b05ae8674a90ddb19ffe7f4b439 | ≥ 6.3.0, ≤ 8.0.2
Vinyl-cache1 product
  • vinyl_cache< 9.0.2 | < 90f5bacc14b2404e6cc349ba015f0f73b8515136

4 vendors · 6 products

References

4 links