CVE-2026-93748: http-cache-semantics through 4.2.0 Cross-User Cache Disclosure via max-stale
Vulnerability summary
CVE-2026-93748 is a high (CVSS 8.7) vulnerability in kornelski http-cache-semantics. EPSS estimates a 0.57% chance of exploitation in the next 30 days, higher than 47.1% of scored vulnerabilities.
Severe, CVSS 8.7 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Timeline
- 18-09-2026PublishedVulnerability first disclosed.
- 14-10-2026Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
13 scores · 7 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- OSV · DebianEcosystem advisory · calculated8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- OSV · WolfiEcosystem advisory · calculated8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- OSV · NpmEcosystem advisory · calculated8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- OSV · ChainguardEcosystem advisory · calculated8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- NVDNIST8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · WolfiEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · NpmEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · ChainguardEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS trend
Probability
0.57%
Chance of exploitation in the next 30 days
Percentile
47%
Versus all other CVEs
30-day change
Increase +0.04 pp
From 0.53% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Chainguard24 products
- actions-runnerAll versions (No fix recorded)
- dotstatsuite-supercoreAll versions (No fix recorded)
- eco-jessAll versions (No fix recorded)
- foxx-cliAll versions (No fix recorded)
- graalvm-25-ce-nodejsAll versions (No fix recorded)
Wolfi8 products
- jupyter-base-notebookAll versions (No fix recorded)
- lernaAll versions (No fix recorded)
- npm-12All versions (No fix recorded)
- prism< 5.16.0-r14
- pulumi-language-nodejsAll versions (No fix recorded)
Debian1 product
- node-gotAll versions (No fix recorded)
Kornelski1 product
- http-cache-semantics≤ 4.2.0
Npm1 product
- http-cache-semantics≤ 4.2.0
Ubuntu1 product
- node-gotAll versions (No fix recorded)
6 vendors · 36 products
References
10 links- github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa8765b633ba880e5e980aa54c/index.jsTechnical DescriptionREPORTWEB
- github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa8765b633ba880e5e980aa54c/index.jsTechnical DescriptionREPORTWEB
