---
id: CVE-2026-93748
title: >-
  http-cache-semantics through 4.2.0 fails to properly validate security-zeroed
  cache entries when processing client max-stale directives, allowing
  unauthenticated attackers to retrieve cached responses belonging to other
  users
summary: >-
  http-cache-semantics through 4.2.0 fails to properly validate security-zeroed
  cache entries when processing client max-stale directives, allowing
  unauthenticated attackers to retrieve cached responses belonging to other
  users. Attackers …
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-524
vendor: kornelski
product: http-cache-semantics
affected:
  - http-cache-semantics <= 4.2.0
published: '2026-09-18'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T17:17:49.593'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93748'
references:
  - url: 'https://github.com/kornelski/http-cache-semantics'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa8765b633ba880e5e980aa54c/index.js#L425-L441
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa8765b633ba880e5e980aa54c/index.js#L603-L623
    label: disclosure@vulncheck.com
  - url: 'https://github.com/kornelski/http-cache-semantics/issues/56'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/http-cache-semantics-through-4.2.0-cross-user-cache-disclosure-via-max-stale
    label: disclosure@vulncheck.com
  - url: 'https://github.com/kornelski/http-cache-semantics/issues/56'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-93748.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-93748'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2538111'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-93748'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93748'
tags:
  - nvd
  - cve.org
  - exploit-available
  - csaf
  - vex
  - red-hat
epss: 0.00531
epssPercentile: 0.42401
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-18T20:05:06.835112Z'
ingestedAt: '2026-09-18T18:47:53.268Z'
---

## Overview

http-cache-semantics through 4.2.0 fails to properly validate security-zeroed cache entries when processing client max-stale directives, allowing unauthenticated attackers to retrieve cached responses belonging to other users. Attackers can request the same URL with a large max-stale value to obtain another user's Set-Cookie session credentials from shared-cache entries that were deliberately zeroed for security reasons.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Hardened Images · no fix planned: Red Hat Hardened Images · updated 2026-09-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-93748.json)