Kong Gateway: Information disclosure via shared cache in request-callout plugin
Summary
The request-callout plugin in Kong Gateway Enterprise and Kong AI Gateway leaves callout headers that the client did not send out of its cache key. A cached callout response for one caller can therefore be served to another caller. An unauthenticated remote attacker can read data that belongs to other callers, and the CVSS impact is limited to confidentiality. The flaw only applies where the request-callout plugin is used with response caching.
Affected
- Kong Gateway Enterprise 3.10.0.0 to before 3.10.0.20
- Kong Gateway Enterprise 3.13.0.0 to before 3.13.0.12
- Kong Gateway Enterprise 3.14.0.0 to before 3.14.0.17
- Kong Gateway Enterprise 3.15.0.0 to before 3.15.0.7
- Kong Gateway Enterprise 3.16.0.0 to before 3.16.0.2
- Kong AI Gateway 2.2.0 to before 2.2.1
Fixed in
- Kong Gateway Enterprise 3.10.0.20
- Kong Gateway Enterprise 3.13.0.12
- Kong Gateway Enterprise 3.14.0.17
- Kong Gateway Enterprise 3.15.0.7
- Kong Gateway Enterprise 3.16.0.2
- Kong AI Gateway 2.2.1
Note: The vendor changelog confirms the fix for CVE-2026-123041 under 3.13.0.12. The other build numbers come from third-party trackers and should be verified against the vendor changelog before rollout.
Workaround
- No vendor workaround known. Unknown.
- Interim measure (own inference): review whether request-callout caching is enabled and disable it where it is not needed.
Exploitation
- No public proof of concept known.
- Not listed in CISA KEV (per Strix).
- No evidence of exploitation in the wild on record (OffSeq, as of 10 Nov 2026).
Our recommendation
- Inventory all Kong Gateway and Kong AI Gateway instances and check whether the request-callout plugin with caching is enabled.
- Plan upgrades to the fixed builds of your release branch.
- Upgrade to the latest fixed build on each branch, since several related cache CVEs (CVE-2026-92558, CVE-2026-92545, CVE-2026-92443) were fixed the same day.
- If the gateway is internet-facing and serves several clients or tenants, prioritise the upgrade.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Kong Gateway changelog developer.konghq.com
- Kong AI Gateway changelog developer.konghq.com
- OffSeq threat radar: CVE-2026-123041 radar.offseq.com
- Strix: CVE-2026-123041 www.strix.ai
- ThreatInt: CVE-2026-123041 cve.threatint.com
- Kong request-callout plugin documentation developer.konghq.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 01:25.
Original description (NVD)
The request-callout plugin in Kong Gateway Enterprise and Kong AI Gateway omits callout headers not sent by the client from its cache key, allowing a cached callout response for a caller to be served to another.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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