Description
tiny-http through 0.12.0 contains an HTTP header injection vulnerability that allows attackers to inject carriage return (0x0D) and line feed (0x0A) bytes into HTTP header values on both request and response sides due to insufficient validation in header parsing and serialization. Attackers can exploit this injection primitive to perform response splitting, cache poisoning, session fixation via Set-Cookie injection, security header override, and request smuggling against line-feed-tolerant backends.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| tiny-http | tiny-http | ≤ 0.12.0 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | rust-tiny-http | No fix yet | — |
| Debian 13 | rust-tiny-http | No fix yet | — |
| Debian 12 | rust-tiny-http | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | rust-tiny-http | No fix yet | — |
| Ubuntu 26.04 LTS | rust-tiny-http | No fix yet | — |
| Ubuntu 24.04 LTS | rust-tiny-http | No fix yet | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 1 repository
-
theopaid/CVE-2026-66753-HTTP-Header-Injection-via-Unvalidated-CR-and-LF-in-Header-Values-tiny_http- ★ 0 · Jul 26, 2026
Security Advisory: HTTP Header Injection via Unvalidated CR and LF in Header Values (tiny_http)
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
References
- Researcher Disclosure technical-description exploit
- https://www.vulncheck.com/advisories/tiny-http-http-response-splitting-via-header-injection third-party-advisory