Trending
CVE-2026-33805

CVE detail

CVE-2026-33805

@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.

CVSS 9.0 · CriticalBuzz score 34.0

Buzz score

Why this CVE is surfacing

Buzz score total 34.0

This all-time snapshot uses the same composite formula as Trending across a 30-year evidence window, rather than a current rolling window.

Buzz score components · mention 19.5 · diversity 14.5 · KEV 0.0 · OTX 0.0 · PoC 0.0

Mention score

19.5

6 evidence mentions in the snapshot

Diversity score

14.5

5 sources across 2 categories

KEV score

0.0

No KEV entry observed

OTX score

0.0

0 OTX pulses

PoC score

0.0

0 repos · best confidence N/A

Best PoC traction

Maximum stars on a matched PoC repo

Why it matters now

Mention timeline

Total mentions: 0; within the 30d window
Peak daily: 0; highest bucket

Evidence

Source links by recency

Newest mentions first

6 source links · newest first

https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33805.jsonsecurity.access.redhat.com
No excerpt available.
Vendor Advisorysecurity.access.redhat.comApr 15, 2026, 11:16 AM
https://bugzilla.redhat.com/show_bug.cgi?id=2458651bugzilla.redhat.com
No excerpt available.
Exploitbugzilla.redhat.comApr 15, 2026, 11:16 AM
https://access.redhat.com/security/cve/CVE-2026-33805access.redhat.com
No excerpt available.
Vendor Advisoryaccess.redhat.comApr 15, 2026, 11:16 AM
https://access.redhat.com/errata/RHSA-2026:10175access.redhat.com
No excerpt available.
Vendor Advisoryaccess.redhat.comApr 15, 2026, 11:16 AM
https://github.com/fastify/fastify-reply-from/security/advisories/GHSA-gwhp-pf74-vj37github.com
No excerpt available.
Exploitgithub.comApr 15, 2026, 11:16 AM
https://cna.openjsf.org/security-advisories.htmlcna.openjsf.org
No excerpt available.
Vendor Advisorycna.openjsf.orgApr 15, 2026, 11:16 AM

Exploit code

Public exploit repository references

Public PoC repositories are third-party, potentially unsafe artifacts. Treat their code as untrusted and use it only on authorized systems in an isolated, least-privilege environment. cvebuzz does not execute the code or verify that an exploit works.

0 repository references · best confidence N/A · max 0 stars

No public PoC repositories have been matched yet.

Related records

Similar CVEs

6 related CVEs with shared weakness or product evidence

CVE-2023-51701
fastify-reply-from is a Fastify plugin to forward the current HTTP request to another server. A reverse proxy server built with `@fastify/reply-from` could misinterpret the incomi…
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CVE-2026-58155
Apache Traffic Server truncates over-long header names, allowing header aliasing, request smuggling, and policy bypass. This issue affects Apache Traffic Server: from 8.0.0 throu…
CVSS 9.2 · Critical
1 mention
CVE-2026-58153
Apache Traffic Server forwards HTTP/2 origin trailers to HTTP/1 clients without proper chunked framing when converting HTTP/2 to HTTP/1. This issue affects Apache Traffic Server:…
CVSS 6.3 · Medium
1 mention
CVE-2026-58150
Apache Traffic Server does not reject Transfer-Encoding in HTTP/2 requests, allowing downgrade request smuggling. This issue affects Apache Traffic Server: from 8.0.0 through 8.1…
CVSS 7.8 · High
1 mention
CVE-2026-57834
Apache Traffic Server allows request smuggling if chunked messages are malformed. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.9, from 9.0.0 through 9.2.14, f…
CVSS 7.0 · High
1 mention
CVE-2026-24033
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Apache Traffic Server. This issue affects Apache Traffic Server: from 10.0.0 thr…
CVSS 6.9 · Medium
1 mention

External lookup

Potential internet exposure

Potential exposure only — not proof of vulnerability.Shodan results indicate potentially internet-exposed products, not confirmed vulnerable systems. They do not confirm that any returned system is vulnerable to CVE-2026-33805.

Product-level CPE searches intentionally omit version fields and NVD version-range or configuration certainty. Verify the exact product version and configuration independently.

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Product CPE queries

Derived from this CVE's existing NVD CPE 2.3 records; the application, operating-system, or hardware part is retained.

cpe:2.3:a:fastify:fastify\/http-proxySearch this product on Shodan
cpe:2.3:a:fastify:reply-fromSearch this product on Shodan

Exact CVE query

Eligible paid Shodan plan required

Shodan's exact vuln: filter is separate from the product searches above and requires an eligible paid Shodan plan.

vuln:CVE-2026-33805Search this CVE on Shodan

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Metadata

Canonical fields

NVD status

Modified

Published

Apr 15, 2026

Modified

Jul 15, 2026

Official record

Authoritative NVD record

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

CWE IDs

Vendor classifications

How this vector reads

CVSS 4.0 base metrics decoded below. This explanation does not recalculate or change the NVD score.

Attack Vector (AV): Network. The vulnerable system can be reached across network boundaries.
Attack Complexity (AC): Low. No special conditions beyond the attacker-controlled steps are required.
Attack Requirements (AT): Present. A prerequisite deployment or execution condition must be present.
Privileges Required (PR): None. The attacker needs no privileges on the vulnerable system.
User Interaction (UI): None. Exploitation does not require a targeted user to act.
Vulnerable System Confidentiality (VC): None. There is no direct impact to this security property.
Vulnerable System Integrity (VI): High. There is a total or serious impact to this security property.
Vulnerable System Availability (VA): None. There is no direct impact to this security property.
Subsequent System Confidentiality (SC): Low. There is a limited impact to this security property.
Subsequent System Integrity (SI): High. There is a total or serious impact to this security property.
Subsequent System Availability (SA): None. There is no direct impact to this security property.

Optional CVSS v4 metrics remain in the raw vector; only base metrics are expanded here.

Signals

Exploitation indicators

0 stored signals · no KEV · 0 OTX pulses