Dashboard / CVE-2026-71303

CVE-2026-71303

HIGH
MEDIUM Priority: 0.02 BB Relevance: 65/100
Published: 2026-08-18 Modified: 2026-10-22 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Interaction Conf. Impact Scope Change

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: None
S: Changed
C: High
I: None
A: None

Description

Lemur manages TLS certificate creation. Prior to 1.9.3, _validate_acme_url enforced ACME_DIRECTORY_HOST_ALLOWLIST when an authority was created, but PUT /api/1/authorities/ passed options to lemur/authorities/service.py without applying the same check. A user holding an authority role could replace the stored acme_url with an internal service or instance-metadata URL such as 169.254.169.254. The next issuance operation loaded that value and passed it to ClientV2.get_directory, causing an outbound request from the Lemur backend. This bypassed the creation-time mitigation for CVE-2026-55166 and could expose internal services or cloud metadata. The fix revalidates acme_url whenever authority options are updated. This issue is fixed in version 1.9.3.

Weakness Classification (1)

References & Advisories (3)

Bug Bounty Relevance

65 / 100
✓ Network accessible
✓ Low complexity
✓ No user interaction

CVSS Score

7.7 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

EPSS — Exploitation Probability

0.28%
Raw Score 0.002770
Percentile 20.1%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00277
2026-10-28
0.00277

Intelligence Sources

nvd ref →

External Links