CVE-2026-42551Public exploitNetwork attack vector

CSRF escalation via unconditional HTTP method override

Published May 13, 2026 · Updated May 13, 2026

Interpretation conflict in Flight before 3.18.1 allows remote attackers to execute unsafe routes through crafted method-override inputs. The Request::getMethod() routine treats the X-HTTP-Method-Override header and _method request parameter as authoritative on every verb, so a GET can be dispatched as DELETE or PUT. An unauthenticated request reaches the flaw when an application exposes an unsafe route, enabling destructive CSRF, verb-gated middleware bypass, or cache poisoning.

CVSS severity7.5
High
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Interpretation conflict in Flight before 3.18.1 allows remote attackers to execute unsafe routes through crafted method-override inputs. The Request::getMethod() routine treats the X-HTTP-Method-Override header and _method request parameter as authoritative on every verb, so a GET can be dispatched as DELETE or PUT. An unauthenticated request reaches the flaw when an application exposes an unsafe route, enabling destructive CSRF, verb-gated middleware bypass, or cache poisoning.

The record

CVE
CVE-2026-42551
Published
May 13, 2026
Updated
May 13, 2026
Vendor
FlightPHP
Product
Flight
Classifications
CWE-436, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 13, 2026CVE publishedPublication date reported by the CVE source.
  2. May 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.18.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FlightPHP · Flightversion=< 3.18.1

Published CVSS scores

7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-436Interpretation Conflict
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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