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CVE-2025-59822

Typelevel Http4s vulnerability

7.5 HIGHPublic exploitEPSS 0.37%
  1. Published23 Sept 2025

Description

Http4s is a Scala interface for HTTP services. In versions from 1.0.0-M1 to before 1.0.0-M45 and before 0.23.31, http4s is vulnerable to HTTP Request Smuggling due to improper handling of HTTP trailer section. This vulnerability could enable attackers to bypass front-end servers security controls, launch targeted attacks against active users, and poison web caches. A pre-requisite for exploitation involves the web application being deployed behind a reverse-proxy that forwards trailer headers. This issue has been patched in versions 1.0.0-M45 and 0.23.31.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityNone
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected products

Typelevel Http4s< 0.23.31 · 1.0.0

Remediation

Fixed in
Typelevel Http4s≥ 0.23.31

References

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Frequently asked

Is CVE-2025-59822 being actively exploited?

CVE-2025-59822 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.37%.

How severe is CVE-2025-59822?

CVE-2025-59822 has a CVSS 3.1 base score of 7.5, rated high. EPSS estimates a 0.37% probability of exploitation.

Which products are affected by CVE-2025-59822?

Affected products include Typelevel Http4s.

How do I fix CVE-2025-59822?

Upgrade affected software to a fixed version, for example Typelevel Http4s 0.23.31 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2025-59822 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.