CVE-2025-34520

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: HIGH) published 2025-08-28. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.8Exploit: NoneExposed: 0

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

An authentication bypass vulnerability in Arcserve Unified Data Protection (UDP) allows unauthenticated attackers to gain unauthorized access to protected functionality or user accounts. By manipulating specific request parameters or exploiting a logic flaw, an attacker can bypass login mechanisms without valid credentials and access administrator-level features. This vulnerability affects all UDP versions prior to 10.2. UDP 10.2 includes the necessary patches and requires no action. Versions 8.0 through 10.1 are supported and require either patch application or upgrade to 10.2. Versions 7.x and earlier are unsupported or out of maintenance and must be upgraded to 10.2 to remediate the issue.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
44(Track)
EG Risk 44/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity98% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
27.1%
KEV
Not listed

Published

August 27, 2025

Last Modified

September 9, 2025

Advisory Details (1)

Auto-updated Jun 6, 2026
No patch confirmed yet.
generic

Arcserve Support Community

https://support.arcserve.com/s/article/Important-Security-Bulletin-Must-read-for-all-Arcserve-UDP-customers-on-all-versions

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 48× 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.

  1. 2026-07-23 02:54 UTCEG score recompute
  2. 2026-07-22 14:07 UTCEPSS rescore
  3. 2026-07-22 14:07 UTCEPSS rescore
  4. 2026-07-21 15:24 UTCEPSS rescore
  5. 2026-07-20 17:07 UTCEPSS rescore
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  10. 2026-07-18 10:04 UTCEPSS rescore
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  12. 2026-07-16 17:02 UTCEPSS rescore
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  21. 2026-07-11 08:27 UTCEPSS rescore
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  25. 2026-07-07 13:45 UTCEPSS rescore
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  1. 2026-07-06 16:27 UTCEPSS rescore
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  8. 2026-06-30 23:22 UTCEPSS rescore
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  10. 2026-06-29 14:06 UTCEPSS rescore
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  12. 2026-06-28 14:07 UTCEPSS rescore
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  16. 2026-06-27 03:08 UTCEPSS rescore
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  18. 2026-06-25 13:49 UTCEPSS rescore
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  20. 2026-06-24 14:04 UTCEPSS rescore
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  22. 2026-06-23 21:32 UTCEPSS rescore
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  24. 2026-06-22 14:25 UTCEPSS rescore
  25. 2026-06-22 14:25 UTCEPSS rescore
  26. 2026-06-21 14:56 UTCEPSS rescore
  27. 2026-06-21 14:56 UTCEPSS rescore
  28. 2026-06-21 01:59 UTCEPSS rescore
  29. 2026-06-21 01:59 UTCEPSS rescore
  30. 2026-06-19 19:25 UTCEPSS rescore
  31. 2026-06-19 19:25 UTCEPSS rescore
  32. 2026-06-18 17:52 UTCEPSS rescore
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  35. 2026-06-16 17:52 UTCEPSS rescore
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  37. 2026-06-14 23:17 UTCEPSS rescore
  38. 2026-06-13 23:00 UTCEPSS rescore
  39. 2026-06-12 23:11 UTCEPSS rescore
  40. 2026-06-11 14:00 UTCEPSS rescore
  41. 2026-06-10 22:18 UTCEPSS rescore
  42. 2026-06-10 13:22 UTCEPSS rescore
  43. 2026-06-08 14:16 UTCEPSS rescore
  44. 2026-06-08 14:16 UTCEPSS rescore
  45. 2026-06-07 15:24 UTCEPSS rescore
  46. 2026-06-06 13:47 UTCEPSS rescore
  47. 2026-06-06 13:47 UTCEPSS rescore
  48. 2026-06-05 22:46 UTCEPSS rescore
  49. 2026-06-05 22:46 UTCEPSS rescore
  50. 2026-06-05 06:10 UTCEPSS rescore
  51. 2026-06-05 06:10 UTCEPSS rescore
  52. 2026-06-04 13:12 UTCEPSS rescore
  53. 2026-06-04 13:12 UTCEPSS rescore
  54. 2026-06-02 20:12 UTCEPSS rescore
  55. 2026-06-01 13:51 UTCEPSS rescore
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  57. 2026-05-31 22:30 UTCEPSS rescore
  58. 2026-05-31 22:30 UTCEPSS rescore
  59. 2026-05-31 00:16 UTCEPSS rescore
  60. 2026-05-29 23:47 UTCEG score recompute
  61. 2026-05-29 23:47 UTCGHSA enrichment
  62. 2026-05-29 13:44 UTCEPSS rescore

Frequently asked(5)

What is CVE-2025-34520?
CVE-2025-34520 is a critical vulnerability published on August 27, 2025. An authentication bypass vulnerability in Arcserve Unified Data Protection (UDP) allows unauthenticated attackers to gain unauthorized access to protected functionality or user accounts. By manipulating specific request parameters or exploiting a logic flaw, an attacker can bypass login mechanisms…
When was CVE-2025-34520 disclosed?
CVE-2025-34520 was first published in the National Vulnerability Database on August 27, 2025, with the most recent update on September 9, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-34520 actively exploited?
CVE-2025-34520 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 27.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2025-34520?
CVE-2025-34520 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2025-34520?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-34520, 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.

Dependency Blast Radius

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