GHSA-hj7x-879w-vrp7 CVE-2026-2835 RUSTSEC-2026-0034
Pingora has HTTP Request Smuggling via HTTP/1.0 and Transfer-Encoding Misparsing
- Severity
- 0.0 / 10
- Critical · CVSS 4.0
- Exploit chance (EPSS)
- 0.79%
- Chance of exploitation in the next 30 days. Higher than 56.36% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
- Fix
0.8.0- Upgrade pingora-core to this version or later
Description
Impact
Pingora versions prior to 0.8.0 improperly allowed HTTP/1.0 request bodies to be close-delimited and incorrectly handled multiple Transfer-Encoding values. This allows an attacker to desync Pingora's request framing from backend servers and smuggle requests to the backend.
This vulnerability primarily affects standalone Pingora deployments in front of certain backends that accept HTTP/1.0 requests. An attacker could exploit this to bypass proxy-level ACL controls and WAF logic, poison caches and upstream connections, or perform cross-user attacks by hijacking sessions.
Note: Cloudflare customers and Cloudflare's CDN infrastructure were not affected by this vulnerability, as its ingress proxy layers rejected ambiguous framing such as invalid Content-Length values and internally forwarded non-ambiguous message length framing headers.
Patches
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 (commits 7f7166d62fa916b9f11b2eb8f9e3c4999e8b9023, 40c3c1e9a43a86b38adeab8da7a2f6eba68b83ad, and 87e2e2fb37edf9be33e3b1d04726293ae6bf2052).
Workarounds
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.
References
See CVE-2026-2835 and the Cloudflare blog post for more details.
Credits
Disclosed responsibly by Rajat Raghav (@xclow3n) through the Cloudflare Bug Bounty Program.
Affected versions
crates.io
| Package | Vulnerable | Fixed in |
|---|---|---|
| pingora-core | < 0.8.0 |
0.8.0 |
| pingora-core | >= 0.0.0-0, < 0.8.0 |
0.8.0 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
pingora-core crates.io → 0.8.0
- cargo
cargo update -p pingora-core --precise 0.8.0
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- High
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- High
- Integrity (subsequent systems)
- High
- Availability (subsequent systems)
- None
CVSS 3.1 9.1
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
Weakness
CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.
How to prevent it
- Implementation: Use a web server that employs a strict HTTP parsing procedure, such as Apache [REF-433].
- Implementation: Use only SSL communication.
- Implementation: Terminate the client session after each request.
- System Configuration: Turn all pages to non-cacheable.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| RUSTSEC-2026-0388 Pingora HTTP/2 :authority and Host header mismatch enables cache poisoning and host-based access control bypass | Not rated yet | Also affects pingora-core |
| RUSTSEC-2026-0389 Pingora HTTP/2 server memory exhaustion through unbounded default header-list and concurrent-stream limits | High | Also affects pingora-core |
| GHSA-xq2h-p299-vjwv Pingora vulnerable to HTTP Request Smuggling via Premature Upgrade | Critical | Also affects pingora-core |
| GHSA-393w-9x6h-8gc7 Pingora update for MadeYouReset HTTP/2 vulnerability | High | Also affects pingora-core |
| RUSTSEC-2025-0070 Pingora MadeYouReset HTTP/2 vulnerability | High | Also affects pingora-core |
| GHSA-93c7-7xqw-w357 Pingora has a Request Smuggling Vulnerability | Medium | Also affects pingora-core |
| EEF-CVE-2026-114216 Chunk extensions accept bare LF and CR, enabling request smuggling in Bandit | Not rated yet | Same weakness, CWE-444 |
| GHSA-pqxq-w44r-73xw AIOHTTP: Pure-Python parser request smuggling | Medium | Same weakness, CWE-444 |
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