NVD - CVE-2026-1525 (original) (raw)
CVE-2026-1525 Detail
Description
Undici allows duplicate HTTP Content-Length headers when they are provided in an array with case-variant names (e.g., Content-Length and content-length). This produces malformed HTTP/1.1 requests with multiple conflicting Content-Length values on the wire. Who is impacted: * Applications using undici.request(), undici.Client, or similar low-level APIs with headers passed as flat arrays * Applications that accept user-controlled header names without case-normalization Potential consequences: * Denial of Service: Strict HTTP parsers (proxies, servers) will reject requests with duplicate Content-Length headers (400 Bad Request) * HTTP Request Smuggling: In deployments where an intermediary and backend interpret duplicate headers inconsistently (e.g., one uses the first value, the other uses the last), this can enable request smuggling attacks leading to ACL bypass, cache poisoning, or credential hijacking
Metrics
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CVSS 4.0 Severity and Vector Strings:
NIST: NVD
N/A
NVD assessment not yet provided.
CVSS 3.x Severity and Vector Strings:
NIST: NVD
Base Score: 9.8 CRITICAL
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA: openjs
Base Score: 6.5 MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
CVSS 2.0 Severity and Vector Strings:
NIST: NVD
Base Score: N/A
NVD assessment not yet provided.
References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://cna.openjsf.org/security-advisories.html | openjs | Vendor Advisory |
| https://cwe.mitre.org/data/definitions/444.html | openjs | Technical Description |
| https://github.com/nodejs/undici/security/advisories/GHSA-2mjp-6q6p-2qxm | openjs | Mitigation Vendor Advisory |
| https://hackerone.com/reports/3556037 | openjs | Permissions Required |
| https://www.rfc-editor.org/rfc/rfc9110.html#section-8.6 | openjs | Technical Description |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-444 | Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') | openjs |
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Change History
2 change records found show changes
Initial Analysis by NIST 3/19/2026 1:29:34 PM
| Action | Type | Old Value | New Value |
|---|---|---|---|
| Added | CVSS V3.1 | AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | |
| Added | CPE Configuration | OR *cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:* versions up to (excluding) 6.24.0 *cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:* versions from (including) 7.0.0 up to (excluding) 7.24.0 | |
| Added | Reference Type | openjs: https://cna.openjsf.org/security-advisories.html Types: Vendor Advisory | |
| Added | Reference Type | openjs: https://cwe.mitre.org/data/definitions/444.html Types: Technical Description | |
| Added | Reference Type | openjs: https://github.com/nodejs/undici/security/advisories/GHSA-2mjp-6q6p-2qxm Types: Mitigation, Vendor Advisory | |
| Added | Reference Type | openjs: https://hackerone.com/reports/3556037 Types: Permissions Required | |
| Added | Reference Type | openjs: https://www.rfc-editor.org/rfc/rfc9110.html#section-8.6 Types: Technical Description |
New CVE Received from openjs 3/12/2026 4:16:02 PM
| Action | Type | Old Value | New Value |
|---|---|---|---|
| Added | Description | Undici allows duplicate HTTP Content-Length headers when they are provided in an array with case-variant names (e.g., Content-Length and content-length). This produces malformed HTTP/1.1 requests with multiple conflicting Content-Length values on the wire. Who is impacted: * Applications using undici.request(), undici.Client, or similar low-level APIs with headers passed as flat arrays * Applications that accept user-controlled header names without case-normalization Potential consequences: * Denial of Service: Strict HTTP parsers (proxies, servers) will reject requests with duplicate Content-Length headers (400 Bad Request) * HTTP Request Smuggling: In deployments where an intermediary and backend interpret duplicate headers inconsistently (e.g., one uses the first value, the other uses the last), this can enable request smuggling attacks leading to ACL bypass, cache poisoning, or credential hijacking | |
| Added | CVSS V3.1 | AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L | |
| Added | CWE | CWE-444 | |
| Added | Reference | https://cna.openjsf.org/security-advisories.html | |
| Added | Reference | https://cwe.mitre.org/data/definitions/444.html | |
| Added | Reference | https://github.com/nodejs/undici/security/advisories/GHSA-2mjp-6q6p-2qxm | |
| Added | Reference | https://hackerone.com/reports/3556037 | |
| Added | Reference | https://www.rfc-editor.org/rfc/rfc9110.html#section-8.6 |
Quick Info
CVE Dictionary Entry:
CVE-2026-1525
NVD Published Date:
03/12/2026
NVD Last Modified:
03/19/2026
Source:
openjs