CVE-2026-41520 | Cillium exposes sensitive information included in the cilium-bugtool debug archive

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Prior to versions 1.17.15, 1.18.9, and 1.19.3, the output of cilium-bugtool can contain sensitive data when the tool is run against Cilium deployments with WireGuard encryption enabled. This issue has been patched in versions 1.17.15, 1.18.9, and 1.19.3.

Published: 2026-05-08 Last update: 2026-05-18 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-41520 is rated Low Risk (31.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.01%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-41520

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-09 0.01%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-41520

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.9 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
1.5 5.8 [email protected]
4.4 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
0.8 3.6 [email protected]

Weakness enumeration for CVE-2026-41520

GitHub Security Advisory for CVE-2026-41520

GHSA-gj49-89wh-h4gj · Severity: high · Ecosystem: go — Cillium exposes sensitive information included in the cilium-bugtool debug archive

Affected software / configurations for CVE-2026-41520

Vendor Product Version Raw CPE
cilium cilium < 1.17.15 cpe:2.3:a:cilium:cilium:*:*:*:*:*:*:*:*
cilium cilium >= 1.18.0, < 1.18.9 cpe:2.3:a:cilium:cilium:*:*:*:*:*:*:*:*
cilium cilium >= 1.19.0, < 1.19.3 cpe:2.3:a:cilium:cilium:*:*:*:*:*:*:*:*

References for CVE-2026-41520

cvelogic Threat Intelligence