CASCACascade Atlas

Evidence dossier

CVE-2025-53521

BigIP APM Vulnerability

66.2–82.5Priority evidence range
As known Jul 19, 2026, 5:00 AM UTCgen-56ccdaf9

Normalized restatement

When a BIG-IP APM access policy is configured on a virtual server, specific malicious traffic can lead to Remote Code Execution (RCE).   Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

State
PUBLISHED
Published
Oct 15, 2025
Updated
Mar 31, 2026
Evidence coverage
85%
CISA KEVCatalog member

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

FIRST EPSS2.21%

2026-07-18 · v2026.06.15 · percentile 80.6%

Source stateNo scored conflict

Distinct CVSS assessments remain side by side; none are averaged.

Source comparison

Who said what

CISA-ADPindependent enrichment
container

CISA ADP Vulnrichment

f5original assertion
container

BigIP APM Vulnerability

CISA KEVoriginal assertion
observed_exploitation

F5 BIG-IP Stack-Based Buffer Overflow Vulnerability

FIRST EPSSoriginal assertion
model_probability

Probability 0.022130000000; percentile 0.806370000000

Applicability

Cited product scope

Trace impact →
F5BIG-IP
[{"status": "affected", "version": "17.5.0", "lessThan": "17.5.1.3", "versionType": "custom"}, {"status": "affected", "version": "17.1.0", "lessThan": "17.1.3", "versionType": "custom"}, {"status": "affected", "version": "16.1.0", "lessThan": "16.1.6.1", "versionType": "custom"}, {"status": "affected", "version": "15.1.0", "lessThan": "15.1.10.8", "versionType": "custom"}]unknown
Unknown vendorUnknown product
cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*; start including 15.1.0; end excluding 15.1.10.8supported
Unknown vendorUnknown product
cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*; start including 16.1.0; end excluding 16.1.6.1supported
Unknown vendorUnknown product
cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*; start including 17.1.0; end excluding 17.1.3supported
Unknown vendorUnknown product
cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*; start including 17.5.0; end excluding 17.5.1.3supported

Assessments

CVSS by origin

9.3
f5sirt@f5.comCVSS 4.0 · role SecondaryCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
9.8
f5sirt@f5.comCVSS 3.1 · role SecondaryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.3
f5CVSS 4.0 · role unknownCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
9.8
f5CVSS 3.1 · role unknownCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Limitations and unknowns

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; unresolved scope remains unknown.
  • NVD-carried upstream facts remain derivative and are not independent corroboration.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Factor D is unknown in Public Core because no accepted canonical mapping-obligation ledger is present.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.