CRLF Injection in Nodejs ‘undici’ via Content-Type
undici is an HTTP/1.1 client, written from scratch for Node.js.`=< undici@5.8.0` users are vulnerable to _CRLF Injection_ on headers when using unsanitized input as request headers, more specifically, inside the `content-type` header. Example: ``` import { request } from 'undici' const unsanitizedContentTypeInput = 'application/json\r\n\r\nGET /foo2 HTTP/1.1' await request('http://localhost:3000, { method: 'GET', headers: { 'content-type': unsanitizedContentTypeInput }, }) ``` The above snippet will perform two requests in a single `request` API call: 1) `http://localhost:3000/` 2) `http://localhost:3000/foo2` This issue was patched in Undici v5.8.1. Sanitize input when sending content-type headers using user input as a workaround.
- Published
- Aug 15, 2022
- Updated
- Jun 17, 2026
- EPSS
- 1.3% · 69th percentile
- CWE
- CWE-74
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Report tools
Action score
21
Monitor
Low priority for now.
- CVSS
- 21 / 40 · 5.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.3%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 5.3
- CNA · GitHub_M
- 5.3
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| nodejs | undici | cpe:2.3:a:nodejs:undici |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- nodejs undicibefore 5.8.2
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
nodejs undici
- =< 5.8.0affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | node-undici | before 5.8.2+dfsg1+~cs18.9.18.1-1 | 5.8.2+dfsg1+~cs18.9.18.1-1 |
| npm | undici | before 5.8.2 | 5.8.2 |
| SUSE:Linux Enterprise Module for Web and Scripting 12 | nodejs16 | before 16.17.0-8.9.1 | 16.17.0-8.9.1 |
| SUSE:Linux Enterprise Module for Web and Scripting 15 SP3 | nodejs16 | before 16.17.0-150300.7.9.1 | 16.17.0-150300.7.9.1 |
| SUSE:Linux Enterprise Module for Web and Scripting 15 SP3 | nodejs16 | before 16.17.0-150300.7.9.1 | 16.17.0-150300.7.9.1 |
| SUSE:Linux Enterprise Module for Web and Scripting 15 SP4 | nodejs16 | before 16.17.0-150400.3.6.1 | 16.17.0-150400.3.6.1 |
| SUSE:Linux Enterprise Module for Web and Scripting 15 SP4 | nodejs16 | before 16.17.0-150400.3.6.1 | 16.17.0-150400.3.6.1 |
Same product
nodejs: all recordsOther highest-scoring records for the same primary product.
- CVE-2022-35949`undici.request` vulnerable to SSRF using absolute URL on `pathname`40Plan
- CVE-2026-1525undici is vulnerable to Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')39Monitor
- CVE-2026-84961undici vulnerable to TLS certificate validation bypass via dropped connect options in BalancedPool36Monitor
- CVE-2026-13697undici vulnerable to cross-user information disclosure and parse-time crash via degenerate private cache directives36Monitor
- CVE-2026-6734undici vulnerable to cross-origin request routing via SOCKS5 proxy pool reuse35Monitor
- CVE-2026-84933undici vulnerable to cross-user cookie disclosure via Set-Cookie caching in shared caches32Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:node-undici | 5.8.2+dfsg1+~cs18.9.18.1-1 · Debian:12 | Package registry (OSV) |
| npm:undici | 5.8.2 | Package registry (OSV) |
| opensuse:nodejs16 | 16.17.0-150400.3.6.1 · openSUSE:Leap 15.4 | Package registry (OSV) |
| suse:nodejs16 | 16.17.0-150400.3.6.1 · SUSE:Linux Enterprise Module for Web and Scripting 15 SP4 | Package registry (OSV) |
| suse:nodejs16 | 16.17.0-8.9.1 · SUSE:Linux Enterprise Module for Web and Scripting 12 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- low · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- Low
- Availability impact
- None
Weakness class (CWE)
CWE-74 · Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- HTTP Request SplittingCAPEC-105likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
- Format String InjectionCAPEC-135likelihood: High · High
- Client-side Injection-induced Buffer OverflowCAPEC-14likelihood: Medium · High
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- github.com/nodejs/undici/commit/66165d604fd0aee70a93ed5c44ad4cc2df395f80
- github.com/nodejs/undici/releases/tag/v5.8.2
Vendor advisories and official records. Exploit/PoC links are deliberately left out.