CVE-2026-123041: Kong Gateway Enterprise (high)

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, so a cached callout response meant for one caller can be served to another. An attacker can exploit this remotely, without logging in and without any action from a user, to read cached callout responses belonging to other callers.

Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.

Read the original description

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.

cve.now Index

25Pcve.now Index 25 of 100 · methodology v3 · provisional

Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
Exposure17/25No login or user action needed per the CVSS vector, reachable over the network without a login · Unknown: No advisory context yet
Reach?/20Unknown. No tracked technology or package matched
Severity8.2/10CVSS 8.2
No patch0/5No signal

What would change the score

Would score about 70 if added to CISA KEV
Would score about 65 if CISA's SSVC rates exploitation active
Would score about 30 if advisories confirm default setups are exposed

How the score works · Rankings

What to do

Upgrade to a fixed version: Kong Gateway Enterprise 3.10.0.20, 3.13.0.12, 3.14.0.17, 3.15.0.7, 3.16.0.2 · Kong AI Gateway 2.2.1.

Check your systems with an agent

Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.

Check whether my systems are affected by CVE-2026-123041 (The request-callout plugin in Kong Gateway Enterprise and Kong AI Gateway omits callout headers not sent by the client from its cache key…), using the cve.now data below.

Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.

What cve.now has for CVE-2026-123041 (entry last updated 2026-11-10):
Affected:
- Kong Inc. Kong Gateway Enterprise: from 3.10.0.0, fixed in 3.10.0.20; from 3.13.0.0, fixed in 3.13.0.12; from 3.14.0.0, fixed in 3.14.0.17; from 3.15.0.0, fixed in 3.15.0.7; from 3.16.0.0, fixed in 3.16.0.2
- Kong Inc. Kong AI Gateway: from 2.2.0, fixed in 2.2.1
Fixed versions: 3.10.0.20, 3.13.0.12, 3.14.0.17, 3.15.0.7, 3.16.0.2, 2.2.1.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-123041 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-123041 only. If you also check another CVE, look up its own KEV status; never assume it from this one.

How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.

Verify against the linked advisories before concluding, and cite the date you read each one:
- https://developer.konghq.com/gateway/changelog/
- https://developer.konghq.com/ai-gateway/changelog/
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.

Entry: https://cve.now/CVE-2026-123041
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-123041.

Timeline

Nov 10, 2026, 9:43 PM UTCCVE published
Nov 10, 2026, 10:18 PM UTCFirst seen by cve.now

Affected versions

Kong Inc. Kong Gateway Enterprise
From 3.10.0.0 · fixed in 3.10.0.20; From 3.13.0.0 · fixed in 3.13.0.12; From 3.14.0.0 · fixed in 3.14.0.17; From 3.15.0.0 · fixed in 3.15.0.7; From 3.16.0.0 · fixed in 3.16.0.2
Kong Inc. Kong AI Gateway
From 2.2.0 · fixed in 2.2.1

Evidence 4

CVE record · 2

Establishes: The identifier and description.

Record
CVE List · CVE-2026-123041
Record
NVD · CVE-2026-123041

Corrections

None so far.

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Questions about CVE-2026-123041

Is CVE-2026-123041 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data

Which versions are affected by CVE-2026-123041?

Kong Gateway Enterprise: from 3.10.0.0 before 3.10.0.20; from 3.13.0.0 before 3.13.0.12; from 3.14.0.0 before 3.14.0.17; from 3.15.0.0 before 3.15.0.7; from 3.16.0.0 before 3.16.0.2. Kong AI Gateway: from 2.2.0 before 2.2.1.Source: cve.now feed data

How do I fix CVE-2026-123041?

Upgrade to a fixed version: Kong Gateway Enterprise 3.10.0.20, 3.13.0.12, 3.14.0.17, 3.15.0.7, 3.16.0.2 · Kong AI Gateway 2.2.1.Source: cve.now feed data

The request-callout plugin in Kong Gateway Enterprise and Kong AI Gateway omits callout headers not sent by the client from its cache key…