6.5

CVE-2026-32762: rack Interpretation Conflict

CVSS: 6.5v3.1MediumAnalyzed
AliasesUBUNTU-CVE-2026-32762DEBIAN-CVE-2026-32762CGA-25pw-6rwm-f354
Published 02-04-2026Last modified 02-04-2026
Open JSON

Vulnerability summary

CVE-2026-32762 is a medium (CVSS 6.5) Interpretation Conflict vulnerability in rack. EPSS estimates a 0.24% chance of exploitation in the next 30 days, higher than 14.7% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.24%
0%100%
Low · +0.07 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 · Related 2
MGASA-2026-0226CGA-39JG-9VR8-XM6FUSN-8182-1

Timeline

  1. 02-04-2026
    PublishedVulnerability first disclosed.
  2. 02-04-2026
    Last modifiedVulnerability information updated.

Description

Rack is a modular Ruby web server interface. From versions 3.0.0.beta1 to before 3.1.21 and 3.2.0 to before 3.2.6, Rack::Utils.forwarded_values parses the RFC 7239 Forwarded header by splitting on semicolons before handling quoted-string values. Because quoted values may legally contain semicolons, a header can be interpreted by Rack as multiple Forwarded directives rather than as a single quoted for value. In deployments where an upstream proxy, WAF, or intermediary validates or preserves quoted Forwarded values differently, this discrepancy can allow an attacker to smuggle host, proto, for, or by parameters through a single header value. This issue has been patched in versions 3.1.21 and 3.2.6.

CVSS metrics

7 scores · 7 sources · 1 version

EPSS trend

Probability

0.24%

Chance of exploitation in the next 30 days

Percentile

15%

Versus all other CVEs

30-day change

+0.07 pp

From 0.18% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.24%

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

Chainguard29 products
  • kube-fluentd-operator< 1.18.2-r67 | < 1.18.2-r60
  • logstash-8.17All versions (No fix recorded)
  • logstash-8.17-iamguarded-compatAll versions (No fix recorded)
  • logstash-8.17-with-output-opensearchAll versions (No fix recorded)
  • logstash-8.18All versions (No fix recorded)
Wolfi4 products
  • kube-fluentd-operator< 1.18.2-r67 | < 1.18.2-r60
  • logstash-9.3< 9.3.3-r2
  • logstash-9.3-iamguarded-compat< 9.3.3-r2
  • logstash-9.3-with-output-opensearch< 9.3.3-r2
Debian1 product
  • ruby-rack< 3.1.20-0+deb13u2 | < 3.2.6-2
Rack1 product
  • rack≥ 3.0.0.beta1, < 3.1.21 | ≥ 3.0.0, < 3.1.21 | ≥ 3.2.0, < 3.2.6
RubyGems1 product
  • rack≥ 3.0.0.beta1, < 3.1.21 | ≥ 3.2.0, < 3.2.6
Ubuntu1 product
  • ruby-rack< 3.1.16-0.1ubuntu0.3 | All versions (No fix recorded)

6 vendors · 37 products

References

9 links