CVE-2026-9678Disclosure(nodejs / undici)

LOWCVSS 5.9 · MEDIUM

Signal is active with 1 mentions in latest observed window

Immediate actions

Patch nodejs undici systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

Impact: Undici's cache interceptor incorrectly classifies some responses as cacheable when the upstream Cache-Control header uses whitespace-padded qualified private or no-cache field names such as private=" authorization" or no-cache="\tauthorization". The parser preserves the surrounding whitespace, so later comparisons against the literal authorization field name fail and the response is stored. In shared-cache mode, this allows a response containing one user's authenticated data to be served from cache to a subsequent caller, including an unauthenticated caller, when both requests resolve to the same cache key. Affected applications are those that explicitly enable the cache interceptor (interceptors.cache()) in shared mode, forward Authorization headers upstream, and receive cacheable responses with non-canonical qualified private or no-cache directives. Patches: Upgrade to undici v7.28.0 or v8.5.0. Workarounds: If upgrade is not immediately possible, disable shared-cache mode for traffic that includes Authorization headers, avoid caching responses to authenticated requests, or add Vary: Authorization upstream.

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0.5/ 10 priority

Sources & remediation

Vendor / third-party advisories

Weakness type (CWE)

CWE-524

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

STABLE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

undici

Threat summary

Patch or workaround signal is available
5 mentions across 3 observed days
Momentum state: stable

What's happening

Patch or workaround mentioned in 2 signals
Technical details provided in 3 signals
Disclosure: 3 classified signals
General: 1 classified signal
Peaked 2d ago at 2 mentions (2026-06-17); latest day: 1
5 total mentions across 3 days

Affected systems

Vendors

nodejs

Products

undici

Deep dive

Activity timeline5 mentions / 3d

Signal classification3 categories

Disclosure

360.0%

Patch

120.0%

General

120.0%

Referenced assets4 URLs

By indicator

Classification over time

Date	Total	Labels

2026-06-17	2	Disclosure1Patch1
2026-06-18	2	Disclosure2
2026-06-24	1	General1

Full discourse5 posts

Matteo Collina@matteocollina136d
Disclosure
🟡 Moderate: Shared-cache disclosure (CVE-2026-9678). The cache interceptor mishandled whitespace-padded Cache-Control like `private=" authorization"`, so authenticated responses could be cached & served to other users in shared mode. v7/v8. Fixed in 7.28.0 / 8.5.0.
Post summary
The text announces the discovery of a shared-cache disclosure (CVE-2026-9678), explains its technical mechanism, and notes the patch releases that address it.
10020294
57.8K followersView on X
Ulises Gascón@kom_256137d
Patch
🚨 Medium-severity security fix in undici (7.28.0, 8.5.0) just released! Patches CVE-2026-9678. undici vulnerable to cross-user information disclosure via shared cache whitespace bypass. https://github.com/nodejs/undici/security/advisories/GHSA-pr7r-676h-xcf6
Post summary
A medium‑severity fix for undici has been released, patching CVE‑2026‑9678, which allows cross‑user information disclosure through a shared cache whitespace bypass.
00020121
5.5K followersView on X
AndrewMohawk⁽ⁿᵘˡˡ⁾@AndrewMohawk130d
General
I'll harp on about @OpenAI codex being awesome, and I see together we have another CVE in nodejs/undici https://github.com/nodejs/undici/security/advisories/GHSA-pr7r-676h-xcf6 https://www.cve.org/CVERecord?id=CVE-2026-9678
Post summary
The tweet simply references the CVE‑2026‑9678 advisory for nodejs/undici, providing links to the official pages, without supplying further technical, exploit, or mitigation information.
00100401
5.3K followersView on X
Vulmon Vulnerability Feed@VulmonFeeds137d
Disclosure
CVE-2026-9678 Cache Bypass Vulnerability in Undici Allowing Unauthorized Access ... https://vulmon.com/vulnerabilitydetails?qid=CVE-2026-9678 Customizable Vulnerability Alerts: https://alerts.vulmon.com/?utm_source=twitter&utm_medium=social&utm_campaign=2102281&utm_content=4
Post summary
A tweet posts a link to a newly announced CVE (CVE‑2026‑9678) describing a cache bypass in Undici that could allow unauthorized access, with no additional technical details, exploits, or mitigation information.
0000047
4.1K followersView on X
CVE@CVEnew137d
Disclosure
CVE-2026-9678 Impact: Undici's cache interceptor incorrectly classifies some responses as cacheable when the upstream Cache-Control header uses whitespace-padded qualified private or… https://www.cve.org/CVERecord?id=CVE-2026-9678
Post summary
The text announces CVE-2026-9678, explaining that Undici’s cache interceptor misclassifies responses due to whitespace in Cache‑Control headers; no PoC, exploit, patch, or active exploitation evidence is provided.
00000182
57.6K followersView on X

CPE platform detail1 entries

Part:

Vendor:

Product:

Version:

Target SW:

Target HW:

1 of 1 entries

Part	Vendor	Product	Version	Target SW	Target HW
App	nodejs	undici	-	node.js	-

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What researchers are saying

CVE-2026-9678

Matteo Collina[verified]@matteocollinaDisclosure

The text announces the discovery of a shared-cache disclosure (CVE-2026-9678), explains its technical mechanism, and notes the patch releases that address it.

Ulises Gascón@kom_256Patch

A medium‑severity fix for undici has been released, patching CVE‑2026‑9678, which allows cross‑user information disclosure through a shared cache whitespace bypass.

AndrewMohawk⁽ⁿᵘˡˡ⁾@AndrewMohawkGeneral

The tweet simply references the CVE‑2026‑9678 advisory for nodejs/undici, providing links to the official pages, without supplying further technical, exploit, or mitigation information.

Vulmon Vulnerability Feed@VulmonFeedsDisclosure

A tweet posts a link to a newly announced CVE (CVE‑2026‑9678) describing a cache bypass in Undici that could allow unauthorized access, with no additional technical details, exploits, or mitigation information.

CVE@CVEnewDisclosure

The text announces CVE-2026-9678, explaining that Undici’s cache interceptor misclassifies responses due to whitespace in Cache‑Control headers; no PoC, exploit, patch, or active exploitation evidence is provided.