http-cache-semantics: Use of Cache Containing Sensitive Information
CVE-2026-93748 is a high-severity use of cache containing sensitive information vulnerability in http-cache-semantics from Kornelski, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected http-cache-semantics versions: 4.2.0 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.6% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of http-cache-semantics you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Kornelski | http-cache-semantics | 4.2.0 and earlier | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.7 | High | CNA (vulncheck.com) |
| CVSS 3.1 | 7.5 | High | CNA (vulncheck.com) |
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Cache Containing Sensitive Information
The code uses a cache that contains sensitive information, but the cache can be read by an actor outside of the intended control sphere.
How developers prevent this class of flaw
- Do not store unnecessarily sensitive information in the cache.
More Use of Cache Containing Sensitive Information vulnerabilities (CWE-524)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
- github.com/kornelski/http-cache-semantics
- github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa8765b633ba880e5e980aa54c/index.js#L425-L441
- github.com/kornelski/http-cache-semantics/blob/f01112e954b83cfa8765b633ba880e5e980aa54c/index.js#L603-L623
- github.com/kornelski/http-cache-semantics/issues/56
- vulncheck.com/advisories/http-cache-semantics-through-4.2.0-cross-user-cache-disclosure-via-max-stale
- github.com/github/advisory-database/issues/10139
- github.com/kornelski/http-cache-semantics/issues/56#issuecomment-5975759591
Recent Use of Cache Containing Sensitive Information vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 8.6 High severity
- 7.1 High severity
Spotted an error? Tell us.