CVE-2026-0865

Published Jan 20, 2026

Last updated 13 days ago

CVSS medium 5.9
Port (80)

Overview

Description
User-controlled header names and values containing newlines can allow injecting HTTP headers.
Source
cna@python.org
NVD status
Awaiting Analysis

Risk scores

CVSS 4.0

Type
Secondary
Base score
5.9
Impact score
-
Exploitability score
-
Vector string
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/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
Severity
MEDIUM

Weaknesses

cna@python.org
CWE-74

Social media

Hype score
Not currently trending

  1. Fedora 42 and 43 ship security updates for python3.9, fixing critical command injection flaws (CVE-2026-1299, CVE-2026-0865, CVE-2025-15366, CVE-2025-15367). Developers should update. #Linux https://t.co/Cimlhntjlp

    @threatcluster

    28 Feb 2026

    108 Impressions

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  2. SUSE releases security updates for Python 3.6 and 3.10 on SLES and openSUSE, patching HTTP header injection flaws CVE-2025-11468, CVE-2026-0672, CVE-2026-0865 and CVE-2025-15366. Users should update. https://t.co/hEVh9iBMWP

    @threatcluster

    25 Feb 2026

    30 Impressions

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Related CVEs

  1. An HTTP request smuggling vulnerability (CWE-444) was found in Pingora's handling of HTTP/1.1 connection upgrades. The issue occurs when a Pingora proxy reads a request containing an Upgrade header, causing the proxy to pass through the rest of the bytes on the connection to a backend before the backend has accepted the upgrade. An attacker can thus directly forward a malicious payload after a request with an Upgrade header to that backend in a way that may be interpreted as a subsequent request header, bypassing proxy-level security controls and enabling cross-user session hijacking. Impact This vulnerability primarily affects standalone Pingora deployments where a Pingora proxy is exposed to external traffic. An attacker could exploit this 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 ingress proxies in the CDN stack maintain proper HTTP parsing boundaries and do not prematurely switch to upgraded connection forwarding mode. Mitigation: Pingora users should upgrade to Pingora v0.8.0 or higher As a workaround, users may return an error on requests with the Upgrade header present in their request filter logic in order to stop processing bytes beyond the request header and disable downstream connection reuse.•CVE-2026-2833
  2. 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.•CVE-2026-2835
  3. cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.35.0, when a request handler throws a C++ exception and the application has not registered a custom exception handler via set_exception_handler(), the library catches the exception and writes its message directly into the HTTP response as a header named EXCEPTION_WHAT. This header is sent to whoever made the request, with no authentication check and no special configuration required to trigger it. The behavior is on by default. A developer who does not know to opt in to set_exception_handler() will ship a server that leaks internal exception messages to any client. This vulnerability is fixed in 0.35.0.•CVE-2026-28434
  4. METIS DFS devices (versions <= oscore 2.1.234-r18) expose a web-based shell at the /console endpoint that does not require authentication. Accessing this endpoint allows a remote attacker to execute arbitrary operating system commands with 'daemon' privileges. This results in the compromise of the software, granting unauthorized access to modify configuration, read and alter sensitive data, or disrupt services.•CVE-2026-2249
  5. Webserver crash caused by scanning on TCP port 80 in Softing Industrial Automation GmbH gateways and switch.This issue affects smartLink HW-PN: from 1.02 through 1.03 smartLink HW-DP: 1.31•CVE-2025-10150

References

Sources include official advisories and independent security research.