undici vulnerable to cross-user information disclosure via whitespace around equals in Cache-Control directives
Noroxi assessment
Priority: Monitor (action score 30/100)
- 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: 0.39% (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.
- Fixed version: undici undici 7.29.0, 8.9.0.
Low priority for now. Upgrade to undici undici 7.29.0, 8.9.0 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's cache interceptor mishandles optional whitespace placed around the equals sign of a qualified no-cache or private Cache-Control directive. In undici from 7.0.0 up to before 7.29.0 and from 8.0.0 up to before 8.9.0, the parser either drops the directive or stores a field name with literal quote characters, so the cache decision fails to recognize the qualification and the response is stored. In shared-cache mode, this lets a response containing one user's authenticated data be served from cache to a later caller, including an unauthenticated one, when both requests resolve to the same cache key. It affects applications that enable the cache interceptor in shared mode, forward Authorization headers upstream, and receive cacheable responses with qualified directives padded with whitespace around the equals sign. This is the whitespace-around-equals variant that the fix for CVE-2026-9678 did not normalize, and it is fixed in undici 7.29.0 and 8.9.0.
- Published
- Jul 29, 2026
- Updated
- Aug 4, 2026
- EPSS
- 0.3% · 32th percentile
- CWE
- CWE-436
Report tools
Action score
30
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 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
- 7.5
- CNA · openjs
- 5.9
- 1.6 point gap
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
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
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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.
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 |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- nodejs undici7.0.0 and later · before 7.29.0
- nodejs undici8.0.0 and later · before 8.9.0
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
- 7.29.0, 8.9.0not affected
- 7.0.0 and later · before 7.29.0affected · semver
- 8.0.0 and later · before 8.9.0affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | node-undici | from 0 | — |
| Debian:14 | node-undici | before 8.9.0+dfsg+~cs3.2.0-1 | 8.9.0+dfsg+~cs3.2.0-1 |
| npm | undici | from 7.0.0 · before 7.29.0 | 7.29.0 |
| npm | undici | from 8.0.0 · before 8.9.0 | 8.9.0 |
| Red Hat:hummingbird:1 | nodejs24 | before 0:24.18.1-0.1.hum1 | 0:24.18.1-0.1.hum1 |
| Red Hat:hummingbird:1 | nodejs24-bin | before 0:24.18.1-0.1.hum1 | 0:24.18.1-0.1.hum1 |
| Red Hat:hummingbird:1 | nodejs24-devel | before 0:24.18.1-0.1.hum1 | 0:24.18.1-0.1.hum1 |
| Red Hat:hummingbird:1 | nodejs24-docs | before 0:24.18.1-0.1.hum1 | 0:24.18.1-0.1.hum1 |
| Red Hat:hummingbird:1 | nodejs24-full-i18n | before 0:24.18.1-0.1.hum1 | 0:24.18.1-0.1.hum1 |
| Red Hat:hummingbird:1 | nodejs24-libs | before 0:24.18.1-0.1.hum1 | 0:24.18.1-0.1.hum1 |
| Red Hat:hummingbird:1 | nodejs24-npm | before 0:11.16.0-1.24.18.1.0.1.hum1 | 0:11.16.0-1.24.18.1.0.1.hum1 |
| Red Hat:hummingbird:1 | nodejs24-npm-bin | before 0:24.18.1-0.1.hum1 | 0:24.18.1-0.1.hum1 |
| Red Hat:hummingbird:1 | nodejs26 | before 0:26.5.1-1.5.hum1 | 0:26.5.1-1.5.hum1 |
| Red Hat:hummingbird:1 | nodejs26-bin | before 0:26.5.1-1.5.hum1 | 0:26.5.1-1.5.hum1 |
| Red Hat:hummingbird:1 | nodejs26-devel | before 0:26.5.1-1.5.hum1 | 0:26.5.1-1.5.hum1 |
| Red Hat:hummingbird:1 | nodejs26-docs | before 0:26.5.1-1.5.hum1 | 0:26.5.1-1.5.hum1 |
| Red Hat:hummingbird:1 | nodejs26-full-i18n | before 0:26.5.1-1.5.hum1 | 0:26.5.1-1.5.hum1 |
| Red Hat:hummingbird:1 | nodejs26-libs | before 0:26.5.1-1.5.hum1 | 0:26.5.1-1.5.hum1 |
| Red Hat:hummingbird:1 | nodejs26-npm | before 0:11.17.0-1.26.5.1.1.5.hum1 | 0:11.17.0-1.26.5.1.1.5.hum1 |
| Red Hat:hummingbird:1 | nodejs26-npm-bin | before 0:26.5.1-1.5.hum1 | 0:26.5.1-1.5.hum1 |
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-2026-16729Jul 29, 2026 · undici vulnerable to cookie attribute injection via unsanitized domain and unparsed setCookie fields26Monitor
- ← EarlierCVE-2026-16728Jul 29, 2026 · undici vulnerable to downstream response desynchronization via retry interceptor26Monitor
- Later →CVE-2026-15157Jul 29, 2026 · undici vulnerable to CRLF Injection via blob-like body 'type' property21Monitor
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 | 7.29.0 | Vendor (CNA) |
| undici undici | 8.9.0 | Vendor (CNA) |
| debian:node-undici | 8.9.0+dfsg+~cs3.2.0-1 · Debian:14 | Package registry (OSV) |
| npm:undici | 7.29.0 | Package registry (OSV) |
| npm:undici | 8.9.0 | Package registry (OSV) |
| red hat:nodejs24 | 0:24.18.1-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs24-bin | 0:24.18.1-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs24-devel | 0:24.18.1-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs24-docs | 0:24.18.1-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs26 | 0:26.5.1-1.5.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs26-bin | 0:26.5.1-1.5.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs26-devel | 0:26.5.1-1.5.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs26-docs | 0:26.5.1-1.5.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs26-full-i18n | 0:26.5.1-1.5.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs26-libs | 0:26.5.1-1.5.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs26-npm | 0:11.17.0-1.26.5.1.1.5.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:nodejs26-npm-bin | 0:26.5.1-1.5.hum1 · Red Hat:hummingbird:1 | Package 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.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
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 researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- rampage0010reporter
- mcollinaremediation developer
- UlisesGasconremediation reviewer
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
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
- none
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
CWE-436 · Interpretation ConflictCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
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.
Change log
- 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.