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VulnerabilityCVE-2025-26399Published 2025-09-23

CVE-2025-26399 — Solarwinds Web Help Desk

criticalCISA KEV

As of 2026-03-10, CVE-2025-26399 is a CRITICAL-severity vulnerability in Solarwinds Web Help Desk, CVSS v3.1 9.8, EPSS 32.2% (96.8th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-03-09), with a US federal remediation deadline of 2026-03-12. Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2025-26399, most recently “GOLD ENCOUNTER / Payouts King Ransomware Campaign Targeting Business Managers: 351 Victims Across 334 Organizations”.

CVSS v3.1
9.8/10Critical
EPSS
32.2%Higher than 96.8% of scored CVEs
CISA KEV
ListedAdded · due 2026-03-12
Tracked threats
1Campaigns referencing it
Priority
9/10Threadlinqs triage score
Published
Updated 2026-03-10
CVSS v3.1 9.8 (CRITICAL) · EPSS 32.2% (higher than 96.8% of all scored CVEs) · Priority 9/10 · Published 2025-09-23

Last updated:

What is CVE-2025-26399?

SolarWinds Web Help Desk was found to be susceptible to an unauthenticated AjaxProxy deserialization remote code execution vulnerability that, if exploited, would allow an attacker to run commands on the host machine. This vulnerability is a patch bypass of CVE-2024-28988, which in turn is a patch bypass of CVE-2024-28986.

The record classifies CVE-2025-26399 under weakness class CWE-502. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 377 days ago.

Severity and exploitation probability

CVSS v3.1 base score
9.8 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (FIRST)
32.2% probability of exploitation in the next 30 days, higher than 96.8% of all scored CVEs
CISA KEV
Listed since 2026-03-09, federal remediation deadline 2026-03-12
Threadlinqs priority
9/10 — CISA KEV-listed, which Threadlinqs floors at 9
Published
2025-09-23, last modified 2026-03-10

Is CVE-2025-26399 being exploited?

CISA added CVE-2025-26399 to the Known Exploited Vulnerabilities catalog on 2026-03-09, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2026-03-12 under BOD 22-01. It currently carries a trending score of 39 in the Threadlinqs vulnerability feed.

Affected products and versions

How to fix CVE-2025-26399

The record marks a vendor fix as available for CVE-2025-26399. Patch reference: https://www.solarwinds.com/trust-center/security-advisories/cve-2025-26399. Vendor advisory: https://www.solarwinds.com/trust-center/security-advisories/CVE-2025-26399. Because CVE-2025-26399 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2026-03-12. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

Threat activity tracking CVE-2025-26399

1 tracked threat in the Threadlinqs corpus references CVE-2025-26399, either in the campaign’s CVE list or as an indicator on the campaign record.

Sources

Seeded from nvd and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.