CVE-2026-33805
Essential information
- Published
- 15/04/2026 11:16
- Modified
- 15/04/2026 14:16
- Author
- —
- Creator
- —
- CVSS
- 9.0 CRITICAL (v3) 9.0 CRITICAL (v4.0)
- CISA KEV
- No
- CWE
- —
- 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
CVSS metrics
- Access vector
- —
- Access complexity
- —
- Authentication
- —
- Confidentiality impact
- —
- Integrity impact
- —
- Availability impact
- —
- Exploitability
- —
- Remediation level
- —
- Report confidence
- —
- Temporal score
- —
- Attack vector
- —
- Attack complexity
- —
- Privileges required
- —
- User interaction
- —
- Scope
- —
- Confidentiality impact
- —
- Integrity impact
- —
- Availability impact
- —
- Exploit code maturity
- —
- Remediation level
- —
- Report confidence
- —
- Temporal score
- —
- Attack vector
- NETWORK
- Attack complexity
- LOW
- Attack requirements
- PRESENT
- Privileges required
- NONE
- User interaction
- NONE
- Confidentiality (V)
- NONE
- Confidentiality (S)
- LOW
- Integrity (V)
- HIGH
- Integrity (S)
- HIGH
- Availability (V)
- NONE
- Availability (S)
- NONE
- Exploit maturity
- NOT_DEFINED
Description
@fastify/reply-from v12.6.1 and earlier and @fastify/http-proxy v11.4.3 and earlier process the client's Connection header after the proxy has added its own headers via rewriteRequestHeaders. This allows attackers to retroactively strip proxy-added headers from upstream requests by listing them in the Connection header value. Any header added by the proxy for routing, access control, or security purposes can be selectively removed by a client. @fastify/http-proxy is also affected as it delegates to @fastify/reply-from.
Upgrade to @fastify/reply-from v12.6.2 or @fastify/http-proxy v11.4.4 or later.
NVD status
- Status
- Received — CVE has been recently published to the CVE List and has been received by the NVD.
- Source
- ce714d77-add3-4f53-aff5-83d477b104bb
- NVD
- View on NVD
Affected products (CPE)
| Product | CPE |
|---|---|
| fastify / reply-from | cpe:2.3:a:fastify:reply-from:12.6.1:*:*:*:*:*:*:* |
| fastify / http-proxy | cpe:2.3:a:fastify:http-proxy:11.4.3:*:*:*:*:*:*:* |