9.8

CVE-2026-34475: varnish-software varnish_cache

CVSS: 9.8v3.1CriticalAnalyzed
AliasesUBUNTU-CVE-2026-34475DEBIAN-CVE-2026-34475
Published 27-03-2026Last modified 27-03-2026
Open JSON

Vulnerability summary

CVE-2026-34475 is a critical (CVSS 9.8) vulnerability in varnish-software varnish_cache. EPSS estimates a 0.37% chance of exploitation in the next 30 days, higher than 29.2% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (NVD)
EPSS score
0.37%
0%100%
Low · +0.17 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1
MGASA-2026-0357

Timeline

  1. 27-03-2026
    PublishedVulnerability first disclosed.
  2. 27-03-2026
    Last modifiedVulnerability information updated.

Description

Varnish Cache before 8.0.1 and Varnish Enterprise before 6.0.16r12, in certain unchecked req.url scenarios, mishandle URLs with a path of / for HTTP/1.1, potentially leading to cache poisoning or authentication bypass.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.37%

Chance of exploitation in the next 30 days

Percentile

29%

Versus all other CVEs

30-day change

+0.17 pp

From 0.20% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.37%

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

Varnish-software2 products
  • varnish_cache< 6.0.17 LTS | ≥ 7.0.0, < 8.0.1
  • varnish_enterprise≤ 6.0.15 | 6.0.16:r1 | 6.0.16:r10 | 6.0.16:r11 | 6.0.16:r2 | 6.0.16:r3 | 6.0.16:r4 | 6.0.16:r5 | 6.0.16:r6 | 6.0.16:r7 | 6.0.16:r8 | 6.0.16:r9
Debian1 product
  • varnishAll versions (No fix recorded)
Ubuntu1 product
  • varnishAll versions (No fix recorded)
Vinyl-cache1 product

4 vendors · 5 products

References

4 links