Back to the CVE list
CVE-2026-109829

undici vulnerable to cache poisoning and cross-user disclosure via cross-origin redirects

CVSS score

7.4

EPSS probability

%0.1

Risk score

0.0

Published

4 d ago

A patch is available only for some products or versions

Kanıt listesindeki ürün ve sürüm eşleşmesini kontrol edin; bazı varyantlar hâlâ etkileniyor olabilir.

Impact on My Inventory

Only the personal products you have added to your account are assessed; an organisation's inventory does not appear here.

Checking session…

Vulnerability description

CVE AI research

The stored explanation is shown at once; refreshing evaluates the sources again.

DayBreach AI Explanation

Verified against sources

undici Cache Poisoning and Cross-User Disclosure Vulnerability

Sources read

2

Source agreement

Tam uyum

Evidence confidence

%63

Short explanation

undici, an HTTP client library for Node.js, is vulnerable to cache poisoning and cross-user data disclosure under specific redirect and cache composition configurations.

Why does it matter?

Attackers can achieve persistent cache poisoning by caching responses under trusted URLs or disclose private user-specific data to unauthenticated callers.

What should be done?

  • Upgrade to undici 7.30.1 or 8.12.2
  • Compose the cache interceptor before the redirect interceptor
  • Use per-origin dispatchers and cache stores
Chain of evidence and sources2 verified claims

undici 7.0.0 ila 7.30.0 ve 8.0.0 ila 8.12.1 sürümleri arasındaki undici kütüphanesi önbellek zehirlenmesine karşı savunmasızdır.

Sorun undici 7.30.1 ve 8.12.2 sürümlerinde giderilmiştir.

Show the technical text from the sources

undici is an HTTP client library for Node.js. In versions 7.0.0 through 7.30.0 and 8.0.0 through 8.12.1, when an originless Agent composes the redirect and cache interceptors in that order with a shared cache store, the cache builds its key from the original request URL before the redirect handler changes the origin, so a response produced after a cross-origin redirect is stored under the original key. An attacker who controls the target of a redirect from a trusted URL can have their response cached under that trusted URL and served to later callers, allowing persistent cache poisoning, and the same key confusion lets a private, non-stored redirect response to a user-specific resource be stored under the original URL and served to a later unauthenticated caller, disclosing private data. Applications are affected only when an originless Agent, a shared cache store, and the redirect-then-cache composition are all used. The issue is fixed in undici 7.30.1 and 8.12.2, which verify the producing origin still matches the cache key and preserve each redirect hop's cache-control policy before storing, and users should upgrade to one of those versions or later. As a workaround, compose the cache interceptor before the redirect interceptor, use per-origin dispatchers and cache stores, or disable shared caching on redirect-capable requests.

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

CWE: CWE-346, CWE-524

Explanation produced with the local gemini-flash-lite-latest model. Numerical metrics and the KEV, patch and exploit statuses are not determined by AI.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-109829 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

IDVENDORPRODUCTACTION
1undiciundici View
2debiannode-undici (sid) View
3debiannode-undici (forky) View
4debiannode-undici (trixie) View
5debiannode-undici (bookworm) View
Total affected vendors: 2|Products: 5

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCOREVERSIONSEVERITYVECTORSOURCE
7.4CVSS V3_1HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NCVE CNA
7.4CVSS V31HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NNVD

Patch and Remediation Guide

Solution & Remediation Advisory

Partial patch

1 düzeltme kanıtı bulundu; en az 3 ürün veya sürüm hâlâ etkileniyor ya da inceleniyor.

debiannode-undici (sid)8.12.2+dfsg+~cs3.2.3-1

Debian sid: 8.12.2+dfsg+~cs3.2.3-1

Confirm the affected product and version against the source evidence above.
Restrict access to internet-facing services and apply network segmentation.
Apply the official update named in the evidence only to the matching product and version.
Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-109829 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-109829 weaknesses.

Attack Vector and Accessibility

ExposureAğ üzerinden
PermissionsGerekmiyor
UserGerekmiyor

Official Sources and Advisories

CVSS Vector Radar Chart

7.4 / 10
Attack VectorNetworkComplexityHighPrivilegesNoneUser Interact.NoneConfidentialityHighIntegrityNoneAvailabilityNone

Vulnerability Scoring Details

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredNone required
User InteractionNone required
Confidentiality (Gizlilik)High
Integrity (Bütünlük)None
Availability (Erişilebilirlik)None

Kısmi yama

1 düzeltme kanıtı bulundu; en az 3 ürün veya sürüm hâlâ etkileniyor ya da inceleniyor.

Follow the vendor

U
undici logo
undici
D
debian logo
debian

Weakness Type (CWE & CAPEC)

Similar Vulnerabilities

Get this vulnerability through the API

Affected products, version ranges, exploitation status and patch information in a single request, with a free key.

curl -H "x-api-key: $DAYBREACH_API_KEY" \
  "https://api.daybreach.dev/api/v1/intel/cves/CVE-2026-109829"