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NVD / CVE Program· CNA openjs

CVE-2026-1525: undici is vulnerable to Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Noroxi assessment

Priority: Monitor (action score 39/100)

  • 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: 0.52% (FIRST EPSS).
  • 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.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: nodejs-docs (AlmaLinux:10) 1:22.22.2-1.el10_1; 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.
  • Severity is disputed: the assigning authority (CNA) scores it 6.5, NVD 9.8.

Low priority for now. Upgrade to nodejs-docs (AlmaLinux:10) 1:22.22.2-1.el10_1; 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 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

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

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Mar 12, 2026
Updated
Jun 17, 2026
EPSS
0.5% · 44th percentile

Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
proof of concept
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
9.8
CNA · openjs
6.5
3.3 point gap

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

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

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  • No public exploit code on record
  • A fix has been released

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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:10nodejs-docsbefore 1:22.22.2-1.el10_11:22.22.2-1.el10_1
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 1:22.22.2-1.module_el8.10.0+4158+e796f37f1:22.22.2-1.module_el8.10.0+4158+e796f37f
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 1:22.22.2-1.module_el8.10.0+4158+e796f37f1:22.22.2-1.module_el8.10.0+4158+e796f37f
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-docsbefore 1:22.22.2-1.module_el8.10.0+4158+e796f37f1:22.22.2-1.module_el8.10.0+4158+e796f37f
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-full-i18nbefore 1:22.22.2-1.module_el8.10.0+4158+e796f37f1:22.22.2-1.module_el8.10.0+4158+e796f37f
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-libsbefore 1:22.22.2-1.module_el8.10.0+4158+e796f37f1:22.22.2-1.module_el8.10.0+4158+e796f37f
AlmaLinux:8nodejs-nodemonbefore 3.0.1-1.module_el8.10.0+4006+3c4165193.0.1-1.module_el8.10.0+4006+3c416519
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-packagingbefore 2021.06-6.module_el8.10.0+4158+e796f37f2021.06-6.module_el8.10.0+4158+e796f37f
AlmaLinux:8nodejs-packaging-bundlerbefore 2021.06-6.module_el8.10.0+4158+e796f37f2021.06-6.module_el8.10.0+4158+e796f37f
AlmaLinux:8nodejs-packaging-bundlerbefore 2021.06-6.module_el8.10.0+4086+70facd4a2021.06-6.module_el8.10.0+4086+70facd4a
AlmaLinux:8npmbefore 1:10.9.7-1.22.22.2.1.module_el8.10.0+4158+e796f37f1:10.9.7-1.22.22.2.1.module_el8.10.0+4158+e796f37f
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:8v8-12.4-develbefore 3:12.4.254.21-1.22.22.2.1.module_el8.10.0+4158+e796f37f3:12.4.254.21-1.22.22.2.1.module_el8.10.0+4158+e796f37f
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

+96

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-2026-109829undici vulnerable to cache poisoning and cross-user disclosure via cross-origin redirects
    36Monitor
  • CVE-2026-109383undici vulnerable to TLS certificate validation bypass via dropped tls options in Agent
    36Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2025-47279May 15, 2025 · undici Denial of Service attack via bad certificate data
    12Monitor
  • ← 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
  • Later →CVE-2026-1526Mar 12, 2026 · undici is vulnerable to Unbounded Memory Consumption in undici WebSocket permessage-deflate Decompression
    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:nodejs1:22.22.2-1.module_el8.10.0+4158+e796f37f · AlmaLinux:8Package registry (OSV)
almalinux:nodejs-devel1:22.22.2-1.module_el8.10.0+4158+e796f37f · AlmaLinux:8Package registry (OSV)
almalinux:nodejs-docs1:22.22.2-1.el10_1 · AlmaLinux:10Package registry (OSV)
almalinux:nodejs-full-i18n1:22.22.2-1.module_el8.10.0+4158+e796f37f · AlmaLinux:8Package registry (OSV)
almalinux:nodejs-libs1:22.22.2-1.module_el8.10.0+4158+e796f37f · AlmaLinux:8Package registry (OSV)
almalinux:nodejs-nodemon3.0.1-1.module_el8.10.0+4006+3c416519 · AlmaLinux:8Package registry (OSV)
almalinux:nodejs-packaging2021.06-6.module_el8.10.0+4158+e796f37f · AlmaLinux:8Package registry (OSV)
almalinux:nodejs-packaging-bundler2021.06-6.module_el8.10.0+4158+e796f37f · AlmaLinux:8Package registry (OSV)
almalinux:nodejs24-docs1:24.14.1-2.el10_1 · AlmaLinux:10Package registry (OSV)
almalinux:npm1:10.9.7-1.22.22.2.1.module_el8.10.0+4158+e796f37f · AlmaLinux:8Package registry (OSV)
almalinux:v8-12.4-devel3:12.4.254.21-1.22.22.2.1.module_el8.10.0+4158+e796f37f · AlmaLinux:8Package 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:nodejs1:22.22.2-1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:nodejs-debuginfo1:22.22.2-1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:nodejs-debugsource1:22.22.2-1.module+el8.10.0+24148+847b6786 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:nodejs-devel1:22.22.2-1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:nodejs-docs1:22.22.2-1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:nodejs-full-i18n1:22.22.2-1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:nodejs-libs1:22.22.2-1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:nodejs-libs-debuginfo1:22.22.2-1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:nodejs-npm1:10.9.7-1.22.22.2.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:nodejs221:22.22.2-1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:nodejs22-debuginfo1:22.22.2-1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:nodejs22-debugsource1:22.22.2-1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
rocky linux:nodejs-nodemon0:3.0.1-1.module+el8.10.0+1666+930e28e8 · Rocky Linux:8Package registry (OSV)
rocky linux:nodejs-packaging0:2021.06-6.module+el8.10.0+40048+6d99f608 · Rocky Linux:8Package registry (OSV)
rocky linux:nodejs221:22.22.2-1.el10_1 · Rocky Linux:10Package registry (OSV)

+1

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-2026-16728139 days apartundici vulnerable to downstream response desynchronization via retry interceptor
    26Monitor
  • CVE-2026-18540176 days apartundici vulnerable to downstream response splitting via retry interceptor
    14Monitor

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
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-444 · Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

CVSS vector

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

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.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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

References

Show all references (4 more)

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

All records