CVE-2026-93748: http-cache-semantics max-stale handling can disclose cross-user cached responses
Affects http-cache-semanticsSource GCVE Database
Not known to be exploited · CVSS 8.7 High.
Data as of 5 Nov 2026, 00:01 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 8.7 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 7.5 |
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 47% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 18 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| npmhttp-cache-semantics | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
### Withdrawn Advisory This advisory has been withdrawn because it's not a valid vulnerability. This link is maintained to preserve external references. ### Original 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.
References
- nvd.nist.gov/vuln/detail/CVE-2026-93748 (opens in a new tab)
- github.com/kornelski/http-cache-semantics/issues/56 (opens in a new tab)
- github.com/kornelski/http-cache-semantics/issues/56 (opens in a new tab)
- github.com/kornelski/http-cache-semantics (opens in a new tab)
- github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa8765b633ba880e5e980aa54c/index.js (opens in a new tab)
- github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa8765b633ba880e5e980aa54c/index.js (opens in a new tab)
- vulncheck.com/advisories/http-cache-semantics-through-4.2.0-cross-user-cache-disclosure-via-max-stale (opens in a new tab)