---
title: "CVE-2026-93748: http-cache-semantics - Information Disclosure"
description: "http-cache-semantics <= 4.2.0 contains an information disclosure vulnerability caused by improper validation of security-zeroed cache entries when processing client max-stale directives, letting unauthenticated attackers retrieve cached responses of other users, exploit requires attacker to send requests with large max-stale values."
url: https://panop.io/threat-heartbeat/CVE-2026-93748/
---

# CVE-2026-93748 http-cache-semantics - Information Disclosure

http-cache-semantics <= 4.2.0 contains an information disclosure vulnerability caused by improper validation of security-zeroed cache entries when processing client max-stale directives, letting unauthenticated attackers retrieve cached responses of other users, exploit requires attacker to send requests with large max-stale values.

CVSS base score 7.5 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.57% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-93748)

## Details

Type

Information Disclosure

Impact

Information Disclosure

CVSS vector

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

Published

18 September 2026

Updated

15 October 2026

Weakness

[CWE-524](https://cwe.mitre.org/data/definitions/524.html)

## Vendor fix

Update to a version later than 4.2.0.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-93748](https://nvd.nist.gov/vuln/detail/CVE-2026-93748)
- [https://github.com/kornelski/http-cache-semantics](https://github.com/kornelski/http-cache-semantics)
- [https://github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa8765b633ba880e5e980aa54c/index.js#L425-L441](https://github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa8765b633ba880e5e980aa54c/index.js#L425-L441)
- [https://github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa8765b633ba880e5e980aa54c/index.js#L603-L623](https://github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa8765b633ba880e5e980aa54c/index.js#L603-L623)
- [https://github.com/kornelski/http-cache-semantics/issues/56](https://github.com/kornelski/http-cache-semantics/issues/56)
- [https://www.vulncheck.com/advisories/http-cache-semantics-through-4.2.0-cross-user-cache-disclosure-via-max-stale](https://www.vulncheck.com/advisories/http-cache-semantics-through-4.2.0-cross-user-cache-disclosure-via-max-stale)
- [https://github.com/kornelski/http-cache-semantics/issues/56#issuecomment-5975759591](https://github.com/kornelski/http-cache-semantics/issues/56#issuecomment-5975759591)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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