What is the CVSS score of CVE-2026-2835?

CVE-2026-2835 has a CVSS 3.1 base score of 9.1 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. EPSS exploitation probability: 0.1%.

Which versions of Pingora are affected by CVE-2026-2835?

A critical HTTP Request Smuggling vulnerability in Pingora could allow attackers to bypass security controls, inject malicious requests, or compromise application integrity without detection.. A patch is available.

How to fix or mitigate CVE-2026-2835?

Within 24 hours: Inventory all systems running Pingora and assess exposure; implement WAF rules to detect/block HTTP smuggling patterns (CL.TE, TE.CL mismatches); enable verbose HTTP request logging. Within 7 days: Segment Pingora instances behind request validation proxies; establish monitoring for anomalous request patterns; conduct threat assessment of internet-facing deployments. Within 30 days: Evaluate alternative reverse proxies if patch timeline is uncertain; prepare emergency patching procedures; execute full security audit of affected systems.

Pingora CVE-2026-2835

CRITICAL

HTTP Request/Response Smuggling (CWE-444)

2026-03-05 cna@cloudflare.com

GHSA-hj7x-879w-vrp7

Code Injection Pingora Cloudflare

9.1

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

9.1 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

Analysis Generated

Mar 12, 2026 - 22:06 vuln.today

CVE Published

Mar 05, 2026 - 00:15 nvd

CRITICAL 9.1

DescriptionCVE.org

An HTTP Request Smuggling vulnerability (CWE-444) has been found in Pingora's parsing of HTTP/1.0 and Transfer-Encoding requests. The issue occurs due to improperly allowing HTTP/1.0 request bodies to be close-delimited and incorrect handling of multiple Transfer-Encoding values, allowing attackers to send HTTP/1.0 requests in a way that would desync Pingora’s request framing from backend servers’.

Impact

This vulnerability primarily affects standalone Pingora deployments in front of certain backends that accept HTTP/1.0 requests. An attacker could craft a malicious payload following this request that Pingora forwards to the backend in order to:

Bypass proxy-level ACL controls and WAF logic
Poison caches and upstream connections, causing subsequent requests from legitimate users to receive responses intended for smuggled requests
Perform cross-user attacks by hijacking sessions or smuggling requests that appear to originate from the trusted proxy IP

Cloudflare's CDN infrastructure was not affected by this vulnerability, as its ingress proxy layers forwarded HTTP/1.1 requests only, rejected ambiguous framing such as invalid Content-Length values, and forwarded a single Transfer-Encoding: chunked header for chunked requests.

Mitigation:

Pingora users should upgrade to Pingora v0.8.0 or higher that fixes this issue by correctly parsing message length headers per RFC 9112 and strictly adhering to more RFC guidelines, including that HTTP request bodies are never close-delimited.

As a workaround, users can reject certain requests with an error in the request filter logic in order to stop processing bytes on the connection and disable downstream connection reuse. The user should reject any non-HTTP/1.1 request, or a request that has invalid Content-Length, multiple Transfer-Encoding headers, or Transfer-Encoding header that is not an exact “chunked” string match.