CVE-2026-11525: undici vulnerable to Set-Cookie SameSite attribute downgrade via permissive substring matching
Noroxi assessment
Priority: Monitor (action score 14/100)
- 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: 0.23% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
- Fixed version: undici undici 6.26.0, 7.28.0, 8.5.0; azl3 nodejs 24.17.0-1 on Azure Linux 3.0 24.17.0-2.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to undici undici 6.26.0, 7.28.0, 8.5.0; azl3 nodejs 24.17.0-1 on Azure Linux 3.0 24.17.0-2 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
Impact: When undici parses a Set-Cookie header, it accepts any SameSite attribute value that contains Strict, Lax, or None as a substring, rather than the case-insensitive exact match specified by RFC 6265. Non-spec values are silently mapped to one of the three standard tokens. For example, SameSite=NoneOfYourBusiness is parsed as None (the most permissive setting), and SameSite=StrictLax is parsed as Lax (a downgrade from Strict). Affected applications are those that consume Set-Cookie headers from server responses (for example via undici's fetch or proxy code paths) and then forward or rely on the parsed sameSite attribute. A malicious or non-compliant server can coerce the consumer's view of a cookie's SameSite policy to a weaker value, silently degrading the SameSite enforcement the cookie is supposed to provide. This was introduced in undici 5.15.0 when the cookies feature was added. Patches: Upgrade to undici v6.26.0, v7.28.0 or v8.5.0. Workarounds: After parsing a Set-Cookie header, validate that the resulting sameSite attribute is one of 'Strict', 'Lax', or 'None' (exact, case-insensitive) before forwarding or relying on it.
- GHSA-g8m3-5g58-fq7m
- ALSA-2026:35841
- ALSA-2026:35842
- ALSA-2026:35891
- ALSA-2026:35892
- ALSA-2026:39868
- ALSA-2026:41947
- openSUSE-SU-2026:11121-1
- openSUSE-SU-2026:21058-1
- openSUSE-SU-2026:21236-1
- RHSA-2026:35841
- RHSA-2026:35842
- RHSA-2026:35891
- RHSA-2026:35892
- RHSA-2026:38236
- RHSA-2026:39868
- RHSA-2026:41947
- RHSA-2026:45783
- RLSA-2026:35841
- RLSA-2026:35842
- Published
- Jun 17, 2026
- Updated
- Jun 25, 2026
- EPSS
- 0.2% · 15th percentile
- CWE
- CWE-183
Report tools
Action score
14
Low priority for now.
- CVSS
- 14 / 40 · 3.7 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · openjs
- 3.7
- 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.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi 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.
We use this product, ask for helpAffected 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.
| Vendor | Product | CPE |
|---|---|---|
| nodejs | undici | cpe:2.3:a:nodejs:undici |
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
- 6.26.0, 7.28.0, 8.5.0not affected
- before 6.26.0affected · semver
- 7.0.0 and later · before 7.28.0affected · semver
- 8.0.0 and later · before 8.5.0affected · semver
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- nodejs undicibefore 6.27.0
- nodejs undici7.0.0 and later · before 7.28.0
- nodejs undici8.0.0 and later · before 8.5.0
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:10 | nodejs | before 1:22.23.1-2.el10_2 | 1:22.23.1-2.el10_2 |
| AlmaLinux:10 | nodejs-devel | before 1:22.23.1-2.el10_2 | 1:22.23.1-2.el10_2 |
| AlmaLinux:10 | nodejs-docs | before 1:22.23.1-2.el10_2 | 1:22.23.1-2.el10_2 |
| AlmaLinux:10 | nodejs-full-i18n | before 1:22.23.1-2.el10_2 | 1:22.23.1-2.el10_2 |
| AlmaLinux:10 | nodejs-libs | before 1:22.23.1-2.el10_2 | 1:22.23.1-2.el10_2 |
| AlmaLinux:10 | nodejs-npm | before 1:10.9.8-1.22.23.1.2.el10_2 | 1:10.9.8-1.22.23.1.2.el10_2 |
| AlmaLinux:10 | nodejs24 | before 1:24.18.0-1.el10_2 | 1:24.18.0-1.el10_2 |
| AlmaLinux:10 | nodejs24-devel | before 1:24.18.0-1.el10_2 | 1:24.18.0-1.el10_2 |
| AlmaLinux:10 | nodejs24-docs | before 1:24.18.0-1.el10_2 | 1:24.18.0-1.el10_2 |
| AlmaLinux:10 | nodejs24-full-i18n | before 1:24.18.0-1.el10_2 | 1:24.18.0-1.el10_2 |
| AlmaLinux:10 | nodejs24-libs | before 1:24.18.0-1.el10_2 | 1:24.18.0-1.el10_2 |
| AlmaLinux:10 | nodejs24-npm | before 1:11.16.0-1.24.18.0.1.el10_2 | 1:11.16.0-1.24.18.0.1.el10_2 |
| AlmaLinux:8 | nodejs | before 1:24.18.0-1.module_el8.10.0+4228+2938bc94 | 1:24.18.0-1.module_el8.10.0+4228+2938bc94 |
| AlmaLinux:8 | nodejs | before 1:22.23.1-1.module_el8.10.0+4231+1bf2f855 | 1:22.23.1-1.module_el8.10.0+4231+1bf2f855 |
| AlmaLinux:8 | nodejs-devel | before 1:22.23.1-1.module_el8.10.0+4231+1bf2f855 | 1:22.23.1-1.module_el8.10.0+4231+1bf2f855 |
| AlmaLinux:8 | nodejs-devel | before 1:24.18.0-1.module_el8.10.0+4228+2938bc94 | 1:24.18.0-1.module_el8.10.0+4228+2938bc94 |
| AlmaLinux:8 | nodejs-docs | before 1:24.18.0-1.module_el8.10.0+4228+2938bc94 | 1:24.18.0-1.module_el8.10.0+4228+2938bc94 |
| AlmaLinux:8 | nodejs-docs | before 1:22.23.1-1.module_el8.10.0+4231+1bf2f855 | 1:22.23.1-1.module_el8.10.0+4231+1bf2f855 |
| AlmaLinux:8 | nodejs-full-i18n | before 1:22.23.1-1.module_el8.10.0+4231+1bf2f855 | 1:22.23.1-1.module_el8.10.0+4231+1bf2f855 |
| AlmaLinux:8 | nodejs-full-i18n | before 1:24.18.0-1.module_el8.10.0+4228+2938bc94 | 1:24.18.0-1.module_el8.10.0+4228+2938bc94 |
| AlmaLinux:8 | nodejs-libs | before 1:22.23.1-1.module_el8.10.0+4231+1bf2f855 | 1:22.23.1-1.module_el8.10.0+4231+1bf2f855 |
| AlmaLinux:8 | nodejs-libs | before 1:24.18.0-1.module_el8.10.0+4228+2938bc94 | 1:24.18.0-1.module_el8.10.0+4228+2938bc94 |
| AlmaLinux:8 | nodejs-nodemon | before 3.0.3-1.module_el8.10.0+4061+f8ceeab9 | 3.0.3-1.module_el8.10.0+4061+f8ceeab9 |
| AlmaLinux:8 | nodejs-nodemon | before 3.0.1-1.module_el8.10.0+3956+47c9ee9f | 3.0.1-1.module_el8.10.0+3956+47c9ee9f |
+96
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-2026-109829undici vulnerable to cache poisoning and cross-user disclosure via cross-origin redirects36Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-12151Jun 17, 2026 · undici WebSocket client vulnerable to denial of service via fragment count bypass30Monitor
- ← EarlierCVE-2026-9675Jun 17, 2026 · undici WebSocket client vulnerable to denial of service via cumulative fragment bypass30Monitor
- Later →CVE-2026-6733Jun 17, 2026 · undici vulnerable to HTTP response queue poisoning via keep-alive socket reuse14Monitor
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 |
|---|---|---|
| undici undici | 6.26.0 | Vendor (CNA) |
| undici undici | 7.28.0 | Vendor (CNA) |
| undici undici | 8.5.0 | Vendor (CNA) |
| azl3 nodejs 24.17.0-1 on Azure Linux 3.0 | 24.17.0-2 · CBL-Mariner Releases | Microsoft (MSRC) |
| almalinux:nodejs | 1:22.23.1-2.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:nodejs-devel | 1:22.23.1-2.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:nodejs-docs | 1:22.23.1-2.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:nodejs-full-i18n | 1:22.23.1-2.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:nodejs-libs | 1:22.23.1-2.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:nodejs-npm | 1:10.9.8-1.22.23.1.2.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:nodejs24 | 1:24.18.0-1.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:nodejs24-devel | 1:24.18.0-1.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:nodejs24-docs | 1:24.18.0-1.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:nodejs24-full-i18n | 1:24.18.0-1.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:nodejs24-libs | 1:24.18.0-1.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:nodejs24-npm | 1:11.16.0-1.24.18.0.1.el10_2 · AlmaLinux:10 | Package registry (OSV) |
| debian:node-undici | 8.5.0+dfsg+~cs3.2.0-1 · Debian:14 | Package registry (OSV) |
| npm:undici | 6.27.0 | Package registry (OSV) |
| npm:undici | 7.28.0 | Package registry (OSV) |
| npm:undici | 8.5.0 | Package registry (OSV) |
| opensuse:nodejs22 | 22.23.0-160000.1.1 · openSUSE:Leap 16.0 | Package registry (OSV) |
| opensuse:nodejs24 | 24.17.0-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| red hat:nodejs | 1:22.23.1-2.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:nodejs-debuginfo | 1:22.23.1-2.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:nodejs-devel | 1:22.23.1-2.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:nodejs24 | 1:24.18.0-1.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:nodejs24-debuginfo | 1:24.18.0-1.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:nodejs24-debugsource | 1:24.18.0-1.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:nodejs24-devel | 1:24.18.0-1.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:nodejs24-docs | 1:24.18.0-1.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
+14
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.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- UlisesGasconremediation reviewer
- KhafraDevremediation reviewer
- mcollinaremediation developer
- tndud042713reporter
Bug bounty scope
The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-0409 · Jun 19, 2026(OpenJS / Node.js Undici Güvenlik Bildirimi)
Not on record for this CVE: EPSS history · patch commit or PR link · variant or chain candidate.
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.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- none
- Integrity
- low · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- Low
- Availability impact
- None
Weakness class (CWE)
CWE-183 · Permissive List of Allowed InputsCVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/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.
Attack patterns (CAPEC)
- Double EncodingCAPEC-120likelihood: Low · Medium
- Using Leading 'Ghost' Character Sequences to Bypass Input FiltersCAPEC-3likelihood: Medium · Medium
- Exploiting Multiple Input Interpretation LayersCAPEC-43likelihood: Medium · High
- Using Unicode Encoding to Bypass Validation LogicCAPEC-71likelihood: Medium · High
ATT&CK techniques
—
Change log (1)
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (1 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.