CVE-2026-2835: https://github.com/cloudflare/pingora · HTTP Request/Response Smuggling
Affects https://github.com/cloudflare/pingoraSource CVE Database V5
Not known to be exploited · CVSS 9.3 Critical : upgrade to 0.8.0 as a priority.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.8% chance of exploitation in 30 days – higher than 57% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0.8.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:H/SI:H/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 4 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade https://github.com/cloudflare/pingora and cloudflare/pingora to 0.8.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Cloudflarehttps://github.com/cloudflare/pingora | Affected
| Fixed in
|
GitHubcloudflare/pingorapkg:github/cloudflare/pingoraOther threats | Affected
| Fixed in
|
GitHubhttps://github.com/cloudflare/pingorapkg:github/https://github.com/cloudflare/pingoraOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
To mitigate CVE-2026-2835, organizations should immediately upgrade all Pingora deployments to version 0.8.0 or later, which includes a fix that enforces strict RFC 9112-compliant parsing of HTTP message length headers and disallows close-delimited HTTP/1.0 request bodies. This upgrade is the most effective and comprehensive solution. As an interim measure, implement request filtering rules to reject any HTTP requests that are not HTTP/1.1, contain invalid or conflicting Content-Length headers, have multiple Transfer-Encoding headers, or have Transfer-Encoding headers that do not exactly match “chunked”. Additionally, disable downstream connection reuse to prevent persistent connection exploitation. Network monitoring should be enhanced to detect anomalous HTTP request patterns indicative of request smuggling attempts. Backend servers should be configured to reject ambiguous or malformed HTTP/1.0 requests where possible. Regularly audit proxy and backend configurations to ensure consistent HTTP parsing behavior and alignment with RFC standards. Finally, maintain awareness of threat intelligence updates for any emerging exploits targeting this vulnerability.
Description
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.