CVE-2023-23936 | CRLF Injection in Nodejs ‘undici’ via host

Exp

Undici is an HTTP/1.1 client for Node.js. Starting with version 2.0.0 and prior to version 5.19.1, the undici library does not protect `host` HTTP header from CRLF injection vulnerabilities. This issue is patched in Undici v5.19.1. As a workaround, sanitize the `headers.host` string before passing to undici.

Published: 2023-02-16 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-23936 is rated High Exploit Risk (63.5/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.13%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2023-23936

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2023-23936

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.34% 1.13% +0.79%
2 2026-04-28 0.40% 0.34% -0.06%
3 2026-04-19 — 0.40% —

Full EPSS history (54 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-23936

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 2.5 [email protected]
5.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.5 [email protected]

Weakness enumeration for CVE-2023-23936

GitHub Security Advisory for CVE-2023-23936

GHSA-5r9g-qh6m-jxff · Severity: medium · Ecosystem: npm — CRLF Injection in Nodejs ‘undici’ via host

OS Trackers for CVE-2023-23936

vendor priority summary link
alpine medium CVE-2023-23936: 1 source package rows (nodejs); 29 state rows across 7 repos (3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 7, open 22. https://security.alpinelinux.org/vuln/CVE-2023-23936
debian not yet assigned CVE-2023-23936 not yet assigned priority: Debian including 1 source packages (node-undici), 4 status rows across 4 suites (bookworm, forky, sid, trixie): resolved 4. https://security-tracker.debian.org/tracker/CVE-2023-23936
redhat medium — https://access.redhat.com/security/cve/CVE-2023-23936
suse medium CVE-2023-23936 severity moderate: SUSE including 69 source package names (16-7.1:nodejs16-16.19.1-150400.3.15.1, 16-7.1:npm16-16.19.1-150400.3.15.1, …), 265 product×package rows across 27 product lines (Container bci/nodejs, SUSE CaaS Platform 4.0, … (27 product lines)): Known Not Affected 154, Fixed 111. https://www.suse.com/security/cve/CVE-2023-23936/
ubuntu medium CVE-2023-23936 medium priority: Ubuntu including 1 source packages (node-undici), 9 status rows across 9 suites (bionic, focal, jammy, kinetic, lunar, mantic, trusty, upstream, xenial): ignored 4, DNE 3, not-affected 1, released 1. https://ubuntu.com/security/CVE-2023-23936

Affected software / configurations for CVE-2023-23936

Vendor Product Version Raw CPE
nodejs node.js >= 16.0.0, < 16.19.1 cpe:2.3:a:nodejs:node.js:*:*:*:*:lts:*:*:*
nodejs node.js >= 18.0.0, < 18.14.1 cpe:2.3:a:nodejs:node.js:*:*:*:*:lts:*:*:*
nodejs node.js >= 19.0.0, < 19.6.1 cpe:2.3:a:nodejs:node.js:*:*:*:*:-:*:*:*
nodejs undici >= 2.0.0, < 5.19.1 cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:*

References for CVE-2023-23936

cvelogic Threat Intelligence