How severe is CVE-2026-32762?

CVE-2026-32762 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-32762 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-32762?

CVE-2026-32762 affects Rack. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-32762?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-32762 have an EU (EUVD) identifier?

Yes. CVE-2026-32762 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18423.

When was CVE-2026-32762 published?

CVE-2026-32762 was published on 2026-04-02 and last updated on 2026-06-17.

CVE-2026-32762

CVE-2026-32762 is a medium-severity vulnerability in Rack with a CVSS 3.x base score of 4.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-436.

Key facts

Severity: Medium (CVSS 3.x base score 4.8)
EPSS exploit prediction: 0% (8th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-18423
Weakness: CWE-436
Affected product: Rack
Published: 2026-04-02
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2026-32762?: 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.
How severe is CVE-2026-32762?: CVE-2026-32762 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-32762 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-32762?: CVE-2026-32762 affects Rack. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-32762?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-32762 have an EU (EUVD) identifier?: Yes. CVE-2026-32762 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18423.
When was CVE-2026-32762 published?: CVE-2026-32762 was published on 2026-04-02 and last updated on 2026-06-17.

References

https://github.com/rack/rack/security/advisories/GHSA-qfgr-crr9-7r49

Affected products (1)

cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*

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