CVE-2026-66753: Rust tiny http · tiny-http through 0.12.0 contains an HTTP header injection vulnerability that allows attackers to inject carriage return (0x0D) and line feed (0x0A)
Affects rust-tiny-httpSource GCVE Database
Not known to be exploited · CVSS 3.7 Low.
Data as of 28 Oct 2026, 05:11 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 22% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 28 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10rust-tiny-httppkg:deb/ubuntu/rust-tiny-http?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSrust-tiny-httppkg:deb/ubuntu/rust-tiny-http?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSrust-tiny-httppkg:deb/ubuntu/rust-tiny-http?arch=source&distro=nobleOther 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
Until a fix is available, users should consider mitigating risks by validating and sanitizing HTTP header inputs at application or proxy layers if feasible. Monitor vendor channels for updates regarding an official fix.
Description
Rust tiny-http versions up to 0.12.0 contain an HTTP header injection vulnerability that permits attackers to inject carriage return and line feed characters into HTTP header values. This flaw arises from insufficient validation during header parsing and serialization on both request and response sides. Exploitation can lead to response splitting, cache poisoning, session fixation via Set-Cookie injection, security header override, and request smuggling against backends tolerant to line feeds. The vulnerability is tracked as CVE-2026-66753 and has a medium severity rating with a CVSS score of 3.7. No official patch or fix information is currently provided.
References
- nvd.nist.gov/vuln/detail/CVE-2026-66753 (opens in a new tab)
- github.com/theopaid/HTTP-Header-Injection-via-Unvalidated-CR-and-LF-in-Header-Values-tiny_http-/tree/master (opens in a new tab)
- vulncheck.com/advisories/tiny-http-http-response-splitting-via-header-injection (opens in a new tab)
- ubuntu.com/security/CVE-2026-66753 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-66753 (opens in a new tab)