CVE-2025-20251

HIGHNVD 8.58.5—
EchelonGraph scoreMEDIUM confidence

Score 8.5 from GitHub Security Advisory (severity: HIGH) published 2025-08-14. NVD baseline CVSS 8.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
8.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

A vulnerability in the Remote Access SSL VPN service for Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker to create or delete arbitrary files on the underlying operating system. If critical system files are manipulated, new Remote Access SSL VPN sessions could be denied and existing sessions could be dropped, causing a denial of service (DoS) condition. An exploited device requires a manual reboot to recover. This vulnerability is due to insufficient input validation when processing HTTP requests. An attacker could exploit this vulnerability by sending crafted HTTP requests to an affected device. A successful exploit could allow the attacker to create or delete files on the underlying operating system, which could cause the Remote Access SSL VPN service to become unresponsive. To exploit this vulnerability, the attacker must be authenticated as a VPN user of the affected device.

CVSS v3
8.5
EG Score
8.5(medium)
EPSS
35.6%
KEV
Not listed

Published

August 14, 2025

Last Modified

April 15, 2026

References (1)

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 10× in last 7d / 42× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 117 total refreshes for this CVE.

  1. 2026-07-22 14:07 UTCEPSS rescore
  2. 2026-07-22 14:07 UTCEPSS rescore
  3. 2026-07-21 15:24 UTCEPSS rescore
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  11. 2026-07-15 16:57 UTCEPSS rescore
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  1. 2026-07-06 02:22 UTCEPSS rescore
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  5. 2026-07-01 15:06 UTCEPSS rescore
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  7. 2026-06-29 14:06 UTCEPSS rescore
  8. 2026-06-28 14:07 UTCEPSS rescore
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  10. 2026-06-28 04:55 UTCEPSS rescore
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  20. 2026-06-21 14:56 UTCEPSS rescore
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  22. 2026-06-21 01:59 UTCEPSS rescore
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  24. 2026-06-19 19:25 UTCEPSS rescore
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  26. 2026-06-18 17:52 UTCEPSS rescore
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  30. 2026-06-15 17:48 UTCEPSS rescore
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  36. 2026-06-10 22:18 UTCEPSS rescore
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  40. 2026-06-07 15:24 UTCEPSS rescore
  41. 2026-06-06 13:47 UTCEPSS rescore
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  43. 2026-06-05 22:46 UTCEPSS rescore
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  45. 2026-06-05 06:10 UTCEPSS rescore
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  47. 2026-06-04 13:11 UTCEPSS rescore
  48. 2026-06-04 13:11 UTCEPSS rescore
  49. 2026-06-02 20:12 UTCEPSS rescore
  50. 2026-06-02 20:12 UTCEPSS rescore
  51. 2026-06-01 13:51 UTCEPSS rescore
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  73. 2026-05-26 07:18 UTCEPSS rescore
  74. 2026-05-24 16:56 UTCEPSS rescore
  75. 2026-05-23 15:20 UTCEPSS rescore

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Frequently asked(5)

What is CVE-2025-20251?
CVE-2025-20251 is a high vulnerability published on August 14, 2025. A vulnerability in the Remote Access SSL VPN service for Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker to create or delete arbitrary files on the underlying operating system. If…
When was CVE-2025-20251 disclosed?
CVE-2025-20251 was first published in the National Vulnerability Database on August 14, 2025, with the most recent update on April 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-20251 actively exploited?
CVE-2025-20251 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 35.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2025-20251?
CVE-2025-20251 has a CVSS v3 base score of 8.5 (NVD).
How do I remediate CVE-2025-20251?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-20251, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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