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NVD / CVE Program· CNA openjs

CVE-2026-1527: undici is vulnerable to CRLF Injection via upgrade option

Noroxi assessment

Priority: Monitor (action score 18/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.31% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • Fixed version: nodejs24-docs (AlmaLinux:10) 1:24.14.1-2.el10_1; nodejs24-npm (AlmaLinux:10) 1:11.11.0-1.24.14.1.2.el10_1; nodejs (AlmaLinux:8) 1:24.14.1-2.module_el8.10.0+4160+4819ac42.

Low priority for now. Upgrade to nodejs24-docs (AlmaLinux:10) 1:24.14.1-2.el10_1; nodejs24-npm (AlmaLinux:10) 1:11.11.0-1.24.14.1.2.el10_1; nodejs (AlmaLinux:8) 1:24.14.1-2.module_el8.10.0+4160+4819ac42 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

ImpactWhen an application passes user-controlled input to the upgrade option of client.request(), an attacker can inject CRLF sequences (\r\n) to: * Inject arbitrary HTTP headers * Terminate the HTTP request prematurely and smuggle raw data to non-HTTP services (Redis, Memcached, Elasticsearch) The vulnerability exists because undici writes the upgrade value directly to the socket without validating for invalid header characters: // lib/dispatcher/client-h1.js:1121 if (upgrade) { header += `connection: upgrade\r\nupgrade: ${upgrade}\r\n` }

MediumCVSS 4.6 · v3.1—No exploit Fix available
Published
Mar 12, 2026
Updated
Jun 17, 2026
EPSS
0.3% · 24th percentile

Report tools

JSON

Action score

18

Monitor

Low priority for now.

CVSS
18 / 40 · 4.6 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · openjs
4.6
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
nodejsundici

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • nodejs undicibefore 6.24.0
  • nodejs undici7.0.0 and later · before 7.24.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (openjs). Independent of NVD's CPE analysis and usually ahead of it.

  • undici undici

    • 6.24.0: 7.24.0not affected
    • < 6.24.0; 7.0.0 < 7.24.0affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10nodejs24-docsbefore 1:24.14.1-2.el10_11:24.14.1-2.el10_1
AlmaLinux:10nodejs24-npmbefore 1:11.11.0-1.24.14.1.2.el10_11:11.11.0-1.24.14.1.2.el10_1
AlmaLinux:8nodejsbefore 1:24.14.1-2.module_el8.10.0+4160+4819ac421:24.14.1-2.module_el8.10.0+4160+4819ac42
AlmaLinux:8nodejs-develbefore 1:24.14.1-2.module_el8.10.0+4160+4819ac421:24.14.1-2.module_el8.10.0+4160+4819ac42
AlmaLinux:8nodejs-docsbefore 1:24.14.1-2.module_el8.10.0+4160+4819ac421:24.14.1-2.module_el8.10.0+4160+4819ac42
AlmaLinux:8nodejs-full-i18nbefore 1:24.14.1-2.module_el8.10.0+4160+4819ac421:24.14.1-2.module_el8.10.0+4160+4819ac42
AlmaLinux:8nodejs-libsbefore 1:24.14.1-2.module_el8.10.0+4160+4819ac421:24.14.1-2.module_el8.10.0+4160+4819ac42
AlmaLinux:8nodejs-nodemonbefore 3.0.3-1.module_el8.10.0+4061+f8ceeab93.0.3-1.module_el8.10.0+4061+f8ceeab9
AlmaLinux:8nodejs-packagingbefore 2021.06-6.module_el8.10.0+4086+70facd4a2021.06-6.module_el8.10.0+4086+70facd4a
AlmaLinux:8nodejs-packaging-bundlerbefore 2021.06-6.module_el8.10.0+4086+70facd4a2021.06-6.module_el8.10.0+4086+70facd4a
AlmaLinux:8npmbefore 1:11.11.0-1.24.14.1.2.module_el8.10.0+4160+4819ac421:11.11.0-1.24.14.1.2.module_el8.10.0+4160+4819ac42
AlmaLinux:8v8-13.6-develbefore 3:13.6.233.17-1.24.14.1.2.module_el8.10.0+4160+4819ac423:13.6.233.17-1.24.14.1.2.module_el8.10.0+4160+4819ac42
AlmaLinux:9nodejsbefore 1:24.14.1-2.module_el9.7.0+222+ef1c61e11:24.14.1-2.module_el9.7.0+222+ef1c61e1
AlmaLinux:9nodejs-develbefore 1:24.14.1-2.module_el9.7.0+222+ef1c61e11:24.14.1-2.module_el9.7.0+222+ef1c61e1
AlmaLinux:9nodejs-docsbefore 1:24.14.1-2.module_el9.7.0+222+ef1c61e11:24.14.1-2.module_el9.7.0+222+ef1c61e1
AlmaLinux:9nodejs-full-i18nbefore 1:24.14.1-2.module_el9.7.0+222+ef1c61e11:24.14.1-2.module_el9.7.0+222+ef1c61e1
AlmaLinux:9nodejs-libsbefore 1:24.14.1-2.module_el9.7.0+222+ef1c61e11:24.14.1-2.module_el9.7.0+222+ef1c61e1
AlmaLinux:9nodejs-nodemonbefore 3.0.3-3.module_el9.7.0+209+ecf6523e3.0.3-3.module_el9.7.0+209+ecf6523e
AlmaLinux:9nodejs-packagingbefore 2021.06-6.module_el9.7.0+209+ecf6523e2021.06-6.module_el9.7.0+209+ecf6523e
AlmaLinux:9nodejs-packaging-bundlerbefore 2021.06-6.module_el9.7.0+198+8bf605ba2021.06-6.module_el9.7.0+198+8bf605ba
AlmaLinux:9npmbefore 1:11.11.0-1.24.14.1.2.module_el9.7.0+222+ef1c61e11:11.11.0-1.24.14.1.2.module_el9.7.0+222+ef1c61e1
AlmaLinux:9v8-13.6-develbefore 3:13.6.233.17-1.24.14.1.2.module_el9.7.0+222+ef1c61e13:13.6.233.17-1.24.14.1.2.module_el9.7.0+222+ef1c61e1
Debian:13node-undicifrom 0—
Debian:14node-undicibefore 7.24.5+dfsg+~cs3.2.0-17.24.5+dfsg+~cs3.2.0-1

+42

Same product

nodejs: all records

Other 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-2026-109829undici vulnerable to cache poisoning and cross-user disclosure via cross-origin redirects
    36Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-22036Jan 14, 2026 · Undici has an unbounded decompression chain in HTTP responses on Node.js Fetch API via Content-Encoding leads to resource exhaustion
    30Monitor
  • ← EarlierCVE-2026-1526Mar 12, 2026 · undici is vulnerable to Unbounded Memory Consumption in undici WebSocket permessage-deflate Decompression
    30Monitor
  • Later →CVE-2026-1528Mar 12, 2026 · undici is vulnerable to Malicious WebSocket 64-bit length overflows undici parser and crashes the client
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
almalinux:nodejs1:24.14.1-2.module_el9.7.0+222+ef1c61e1 · AlmaLinux:9Package registry (OSV)
almalinux:nodejs-devel1:24.14.1-2.module_el9.7.0+222+ef1c61e1 · AlmaLinux:9Package registry (OSV)
almalinux:nodejs-docs1:24.14.1-2.module_el9.7.0+222+ef1c61e1 · AlmaLinux:9Package registry (OSV)
almalinux:nodejs-full-i18n1:24.14.1-2.module_el9.7.0+222+ef1c61e1 · AlmaLinux:9Package registry (OSV)
almalinux:nodejs-libs1:24.14.1-2.module_el9.7.0+222+ef1c61e1 · AlmaLinux:9Package registry (OSV)
almalinux:nodejs-nodemon3.0.3-3.module_el9.7.0+209+ecf6523e · AlmaLinux:9Package registry (OSV)
almalinux:nodejs-packaging2021.06-6.module_el9.7.0+209+ecf6523e · AlmaLinux:9Package registry (OSV)
almalinux:nodejs-packaging-bundler2021.06-6.module_el9.7.0+198+8bf605ba · AlmaLinux:9Package registry (OSV)
almalinux:nodejs24-docs1:24.14.1-2.el10_1 · AlmaLinux:10Package registry (OSV)
almalinux:nodejs24-npm1:11.11.0-1.24.14.1.2.el10_1 · AlmaLinux:10Package registry (OSV)
almalinux:npm1:11.11.0-1.24.14.1.2.module_el9.7.0+222+ef1c61e1 · AlmaLinux:9Package registry (OSV)
almalinux:v8-13.6-devel3:13.6.233.17-1.24.14.1.2.module_el9.7.0+222+ef1c61e1 · AlmaLinux:9Package registry (OSV)
debian:node-undici7.24.5+dfsg+~cs3.2.0-1 · Debian:14Package registry (OSV)
npm:undici6.24.0Package registry (OSV)
npm:undici7.24.0Package registry (OSV)
red hat:nodejs1:24.14.1-2.module+el9.7.0+24166+51c9666b · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:nodejs-debuginfo1:24.14.1-2.module+el9.7.0+24166+51c9666b · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:nodejs-debugsource1:24.14.1-2.module+el9.7.0+24166+51c9666b · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:nodejs-devel1:24.14.1-2.module+el9.7.0+24166+51c9666b · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:nodejs-docs1:24.14.1-2.module+el9.7.0+24166+51c9666b · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:nodejs-full-i18n1:24.14.1-2.module+el9.7.0+24166+51c9666b · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:nodejs-libs1:24.14.1-2.module+el9.7.0+24166+51c9666b · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:nodejs-libs-debuginfo1:24.14.1-2.module+el9.7.0+24166+51c9666b · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:nodejs-nodemon0:3.0.3-3.module+el9.7.0+24166+51c9666b · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:nodejs-packaging0:2021.06-6.module+el9.7.0+24166+51c9666b · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:nodejs-packaging-bundler0:2021.06-6.module+el9.7.0+24166+51c9666b · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:npm1:11.11.0-1.24.14.1.2.module+el9.7.0+24166+51c9666b · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
rocky linux:nodejs-nodemon0:3.0.3-3.module+el9.7.0+40025+0e0cf6b2 · Rocky Linux:9Package registry (OSV)
rocky linux:nodejs-packaging0:2021.06-6.module+el9.7.0+40052+e32ea525 · Rocky Linux:9Package registry (OSV)
rocky linux:nodejs241:24.14.1-2.el10_1 · Rocky Linux:10Package 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.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-967997 days apartundici vulnerable to HTTP header injection via Set-Cookie percent-decoding
    23Monitor
  • CVE-2026-15157139 days apartundici vulnerable to CRLF Injection via blob-like body 'type' property
    21Monitor

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.
  • A low-privileged account is enough.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
low · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
Required
Scope
Unchanged
Confidentiality impact
Low
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-93 · Improper Neutralization of CRLF Sequences ('CRLF Injection')

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records