CVE-2026-66753
tiny-http 0.12.0 HTTP Response Splitting via Header Injection
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.
INFO
Published Date :
July 28, 2026, 4:20 p.m.
Last Modified :
July 28, 2026, 5:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-66753
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | LOW | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 4.0 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update tiny-http to a version that addresses header injection.
- Sanitize user-supplied data used in HTTP headers.
- Implement strict validation for CR/LF characters in headers.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-66753.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-66753 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-66753
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-66753 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-66753 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
Jul. 28, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N Removed CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N -
New CVE Received by [email protected]
Jul. 28, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/tiny-http/tiny-http', 'vendor': 'tiny-http', 'product': 'tiny-http', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '0.12.0'}], 'packageURL': 'pkg:github/tiny-http/tiny-http', 'defaultStatus': 'affected'}] Added 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. Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Added CWE CWE-113 Added Reference https://github.com/theopaid/HTTP-Header-Injection-via-Unvalidated-CR-and-LF-in-Header-Values-tiny_http-/tree/master Added Reference https://www.vulncheck.com/advisories/tiny-http-http-response-splitting-via-header-injection