Cyber Resilience

CVE-2025-40553

RCE in Solarwinds Web Help Desk ≤ 2026.1

Published
28 January 2026
Modified
26 February 2026
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.60 99.1th percentile
Risk Priority 94 floored blend · peak EPSS

Summary

CVE-2025-40553 is a critical-severity Deserialization of Untrusted Data (CWE-502) vulnerability in Solarwinds Web Help Desk. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 0.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2025-40553 is an untrusted data deserialization vulnerability (CWE-502) in SolarWinds Web Help Desk that enables remote code execution. Published on 2026-01-28, it allows attackers to run arbitrary commands on the host machine and carries a critical CVSS score of 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

The vulnerability can be exploited remotely over the network with low complexity and without authentication or user interaction by any attacker who can reach the affected Web Help Desk instance. Successful exploitation provides high-impact remote code execution on the server, potentially compromising confidentiality, integrity, and availability of the host system.

SolarWinds addresses the issue in its security advisory at https://www.solarwinds.com/trust-center/security-advisories/CVE-2025-40553 and Web Help Desk 2026.1 release notes at https://documentation.solarwinds.com/en/success_center/whd/content/release_notes/whd_2026-1_release_notes.htm. A proof-of-concept exploit script for this CVE and CVE-2025-40552 is publicly available on GitHub at https://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.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-28986Same product: Solarwinds Web Help Desk
CVE-2025-26399Same product: Solarwinds Web Help Desk
CVE-2025-40551Same product: Solarwinds Web Help Desk
CVE-2024-28988Same product: Solarwinds Web Help Desk
CVE-2024-45709Same product: Solarwinds Web Help Desk
CVE-2025-26400Same product: Solarwinds Web Help Desk
CVE-2025-40552Same product: Solarwinds Web Help Desk
CVE-2025-40554Same product: Solarwinds Web Help Desk
CVE-2026-28299Same product: Solarwinds Web Help Desk
CVE-2023-35184Same product class: network monitoring / SIEM

Affected Assets

solarwinds
web help desk
≤ 2026.1

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can uncover deserialization flaws before deployment.

Input validation directly stops deserialization of untrusted data by ensuring inputs are valid before processing.

Engineering principles such as safe deserialization and input sanitization structurally prevent the weakness from being introduced.

Integrity verification tools can detect malformed or tampered serialized data after the fact.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-02 none match
prevents

PR.PS-02 addresses only post-deployment updates/patching and cannot prevent introduction of unsafe deserialization code, yet it can remediate some instances when the flaw exists in outdated libraries or components.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing includes validation of deserialization routines and the use of untrusted data, reducing the likelihood that unsafe object reconstruction will be deployed.

prevents

Requiring vetted libraries, regular updates and SAST before release reduces the likelihood that deserialization logic will accept and act on attacker-controlled serialized objects.

finds

Regular scanning of third-party libraries and timely patching reduce the likelihood that unsafe deserialization vulnerabilities remain active.

none

Mandatory malware scanning of data received over networks or storage media intercepts malicious serialized payloads before they are deserialized by the target application.

References