CVE-2026-93748Network attack vectorHinoki check available

Cross-user session disclosure via max-stale reuse

Published Sep 18, 2026 · Updated Sep 18, 2026

Cache-policy bypass in http-cache-semantics 4.2.0 and earlier allows remote attackers to read other users' cached session credentials. In satisfiesWithoutRevalidation, the stale-serving branch checks must-revalidate but honors attacker-controlled max-stale even when maxAge has been zeroed for Set-Cookie or proxy-revalidate responses. Exposure requires a shared cache to retain the response and consult the affected policy method, after which an unauthenticated request can receive another user's response headers and body.

CVSS severity8.7
High
EPSS probability0.57%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Cache-policy bypass in http-cache-semantics 4.2.0 and earlier allows remote attackers to read other users' cached session credentials. In satisfiesWithoutRevalidation, the stale-serving branch checks must-revalidate but honors attacker-controlled max-stale even when maxAge has been zeroed for Set-Cookie or proxy-revalidate responses. Exposure requires a shared cache to retain the response and consult the affected policy method, after which an unauthenticated request can receive another user's response headers and body.

The record

CVE
CVE-2026-93748
Published
Sep 18, 2026
Updated
Sep 18, 2026
Vendor
Kornel Lesiński
Product
http-cache-semantics
Classifications
CWE-524, T1539
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=4.2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Kornel Lesiński · http-cache-semanticsversion=0 <=4.2.0

Published CVSS scores

7.5VulnCheck CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
8.7VulnCheck CNACVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-524Use of Cache Containing Sensitive Information
T1539Steal Web Session Cookie

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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