CVE-2026-2835 — HTTP Request Smuggling via HTTP/1.0 and Transfer-Encoding Misparsing

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…

Published Mar 4, 2026Updated Mar 6, 2026Sources: cvelistV5, cloudflare

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

chance of exploitation in 30 days

Affects

cloudflare

https_github_com_cloudflare_pingora

CVSS base

9.3

CRITICAL

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

None

none · proof-of-concept · active

Automatable

Yes

can an attacker script all four kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Affected scope

The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.

Vendors (1)

cloudflare

Products (1)

https github com cloudflare pingora

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
9.3	CVSS 4.0	CRITICAL	—	—	cvelistV5

Weakness & attack patterns

CWE-444

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Search application, proxy, and WAF logs for requests touching /1.0.

References

1 on the record

github.com/cloudflare/pingora
reference

Elsewhere on this site

cloudflareevery CVE for this vendor
CWE-444other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.