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CVE-2025-61882 exploitation attempt

SIGhighconfidence 90/100generated 2026-10-18

Web request carrying the exploit observable of CVE-2025-61882 (CISA KEV, EPSS 1.00, public PoC), taken from the public nuclei template.

ATT&CK: T1190 mitre ↗
Linked CVE: CVE-2025-61882
False positives: Keys on the distinctive part of the exploit request only (path traversal, exploit syntax in the query, an unusual parameter) — never on an endpoint the product serves in normal use. Needs raw request-URI logging (some web servers normalise ../ away). Scanners hitting the internet produce true-positive ATTEMPTS: correlate with sc-status / response size before declaring compromise.

Sigma rule

skopnix-sigma-cve-cve-2025-61882-079b9778.ymldownload .yml ↓

title: Skopnix - CVE-2025-61882 exploitation attempt
id: 7b9aea83-ab2e-5768-a716-e8062d793260
status: experimental
description: Web request carrying the exploit observable of CVE-2025-61882 (CISA KEV, EPSS 1.00, public PoC), taken from the public nuclei template.
references:
  - https://skopnix.com/cve/CVE-2025-61882
  - https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2025/CVE-2025-61882.yaml
  - https://nvd.nist.gov/vuln/detail/CVE-2025-61882
author: skopnix
date: '2026-10-18'
tags:
  - attack.initial-access
  - attack.t1190
  - cve.2025-61882
logsource:
  category: webserver
detection:
  selection_1:
    cs-uri-stem|contains: /OA_HTML/help/../
  condition: selection_1
falsepositives:
  - Vulnerability scanners and authorised penetration tests (attempts, not compromise)
level: critical

How to deploy on Sigma

1.Convert for your SIEM with sigma-cli / pySigma, e.g. sigma convert -t splunk -p sysmon rule.yml.
2.Run it as a hunt first: every rule ships as status experimental.
3.Promote to an alert once a week of results is clean on your data.

Check · The processing pipeline must map the logsource (firewall, dns, proxy, webserver, process_creation) to your field names.

Sigma rule

How to deploy on Sigma

References