8.9

CVE-2026-56742: Cilium: Namespaced HTTPRoutes can redirect traffic to other namespaces

Analyzed
AliasesCGA-2769-9g8m-87g5CGA-35rf-xphx-7p5rCGA-42rm-5795-65pj
Published 15-07-2026Last modified 16-07-2026

Vulnerability summary

CVE-2026-56742 is a high (CVSS 8.9) Missing Authorization vulnerability in cilium. EPSS estimates a 0.17% chance of exploitation in the next 30 days, higher than 6.2% of scored vulnerabilities.

Overall risk
36/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.9/10
010
High · v3.1 (NVD)
EPSS score
0.17%
0%100%
Low · -0.10 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 0 · Related 1
CGA-QQ3J-JCC8-3XJ6

Timeline

  1. 15-07-2026
    PublishedVulnerability first disclosed.
  2. 16-07-2026
    Last modifiedVulnerability information updated.

Description

Cilium is a networking, observability, and security solution. Prior to 1.17.17, 1.18.11, and 1.19.5, Cilium clusters using Gateway API allow users with permissions to create or update namespaced HTTPRoutes to mirror HTTP traffic to any Service in any namespace, bypassing the ReferenceGrant authorization mechanism. Gateway API functionality is disabled by default. This issue is fixed in versions 1.17.17, 1.18.11, and 1.19.5.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.17%

Chance of exploitation in the next 30 days

Percentile

6%

Versus all other CVEs

30-day change

Decrease -0.10 pp

From 0.28% on 22-09-2026

22-09-202622-10-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Chainguard24 products
  • cilium-1.16All versions (No fix recorded)
  • cilium-1.16-clustermesh-apiserverAll versions (No fix recorded)
  • cilium-1.16-hubble-relayAll versions (No fix recorded)
  • cilium-1.16-operator-awsAll versions (No fix recorded)
  • cilium-1.16-operator-genericAll versions (No fix recorded)
Wolfi5 products
  • cilium-1.19-operator-genericAll versions (No fix recorded)
  • hubble< 1.19.4-r6
  • hubble-ui-backend< 0.13.5-r11
  • kubescape< 4.0.10-r8
  • kubescape-operator< 0.2.151-r7 | < 0.2.172-r2
Github.com/cilium2 products
  • cilium< 1.17.17 | ≥ 1.19.0, < 1.19.5
  • ciliumCilium≥ 1.18.0, < 1.18.11
Cilium1 product
  • cilium< 1.17.17 | ≥ 1.18.0, < 1.18.11 | ≥ 1.19.0, < 1.19.5

4 vendors · 32 products

References

11 links
Show all 11 references