What is CVE-2026-15509?
A vulnerability has been found in Leantime up to 3.8.0. This impacts the function editUser/addUser of the component JSON-RPC Endpoint. The manipulation of the argument role leads to improper authorization. The attack is possible to be carried out remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
The record classifies CVE-2026-15509 under weakness classes CWE-285, CWE-266. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 85 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 6.3 — MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R - CVSS v4.0 base score
- 5.3
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P - EPSS (FIRST)
- 0.3% probability of exploitation in the next 30 days, higher than 25.3% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 6.2/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-07-12
Is CVE-2026-15509 being exploited?
Weaponised exploit code for CVE-2026-15509 is publicly available. 1 public proof-of-concept repository is tracked for this identifier. It currently carries a trending score of 44 in the Threadlinqs vulnerability feed.
- trickest/cve (trickest)
Affected products and versions
- (vendor unspecified): Leantime
How to fix CVE-2026-15509
No vendor patch reference has been recorded for CVE-2026-15509 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-15509
No threat campaign in the Threadlinqs corpus currently references CVE-2026-15509, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.
Sources
Enriched from CVE.org, GitHub Security Advisories, FIRST EPSS, public proof-of-concept repositories. Last verified by Threadlinqs on .