synced 11 MIN AGO
01 Record

CVE-2026-33805

@fastify/reply-from vulnerable to connection header abuse enabling stripping of proxy-added headers

CriticalPUBLISHEDCNA: openjs
CNA base score9.0 CVSS v4.0CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:L/SI:H/SA:N
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02 Description

@fastify/reply-from vulnerable to connection header abuse enabling stripping of proxy-added headers

03 Exploitation and scoring

Exploitation
Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.
SSVC decision
  • ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
  • AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.44% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 38.0% of scored records. A rank, not a probability.
NVD base score
9.0 (CVSS v4.0), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:L/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD analysis status
Modified. NVD last modified this record on 2026-10-26.
Red Hat severity
Important. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2026-04-15 10:13Z6 MO AGO
Last updated
2026-07-15 01:06Z3 MO AGO
Reserved
2026-03-23
Assigning CNA
openjs
Record state
PUBLISHED
Severity
Critical (CVSS 9.0)
CNA CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:L/SI:H/SA:N
Weaknesses
  • CWE-644Improper Neutralization of HTTP Headers for Scripting SyntaxVariant
  • CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')Base
Data version
5.2
Document digest
294755384317aaaed6c1f664136f875f480d572d7d6952286b314f21f5a4c8d2

05 Affected products

VendorProductVersionsPlatforms
@fastify/reply-from@fastify/reply-from0 to < 12.6.2—
@fastify/reply-from@fastify/http-proxy0 to < 11.4.4—

06 References