CVE-2025-40553: SolarWinds Web Help Desk · Deserialization of Untrusted Data
Affects SolarWinds Web Help DeskSource CVE Database V5
Not known to be exploited · 67% EPSS · CVSS 9.8 Critical.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 67.9% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 28 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| SolarWindsWeb Help Desk | Affected
| Fixed in– |
AI-suggested
1. Immediate mitigation should focus on isolating SolarWinds Web Help Desk instances from untrusted networks using network segmentation and firewall rules to restrict access to trusted IP addresses only. 2. Monitor network traffic for unusual or suspicious serialized data payloads targeting the Web Help Desk application. 3. Apply vendor patches as soon as they become available; in the absence of patches, consider upgrading to unaffected versions or temporarily disabling the service if feasible. 4. Implement Web Application Firewalls (WAFs) with custom rules to detect and block malicious deserialization attempts. 5. Conduct thorough code reviews and security testing focusing on deserialization processes in custom integrations or plugins related to the Web Help Desk. 6. Employ runtime application self-protection (RASP) tools to detect and prevent exploitation attempts in real-time. 7. Maintain robust incident response plans to quickly contain and remediate any exploitation attempts. 8. Educate IT and security teams about the risks of deserialization vulnerabilities and the importance of secure coding practices to prevent similar issues in the future.
Description
SolarWinds Web Help Desk was found to be susceptible to an untrusted data deserialization vulnerability that could lead to remote code execution, which would allow an attacker to run commands on the host machine. This could be exploited without authentication.
References
- solarwinds.com/trust-center/security-advisories/CVE-2025-40553 (opens in a new tab)
- documentation.solarwinds.com/en/success_center/whd/content/release_notes/whd_2026-1_release_notes.htm (opens in a new tab)
- github.com/watchtowrlabs/watchTowr-vs-SolarWinds-WebHelpDesk-CVE-2025-40552-CVE-2025-40553/blob/main/watchTowr-vs-SolarWinds-WebHelpDesk-CVE-2025-40552-CVE-2025-40553.py (opens in a new tab)