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Fencer Intel
medium 6.1

CVE-2018-5521 json

On F5 BIG-IP 12.1.0-12.1.3.1, 11.6.1-11.6.3.1, 11.5.1-11.5.5, or 11.2.1, carefully crafted URLs can be used to reflect arbitrary content in…

published 8y ago modified 4mo ago also EUVD-2018-17290

cvss
6.1
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 59%
public exploits
0
none known

Summary

On F5 BIG-IP 12.1.0-12.1.3.1, 11.6.1-11.6.3.1, 11.5.1-11.5.5, or 11.2.1, carefully crafted URLs can be used to reflect arbitrary content into GeoIP lookup responses, potentially exposing clients to XSS.

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Exploit prediction

0.89% chance of exploitation in the next 30 days, higher than 59% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.0 6.1 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N

Affected products

  • F5 Networks, Inc. BIG-IP (LTM, AAM, AFM, Analytics, APM, ASM, DNS, Edge Gateway, FPS, GTM, Link Controller, PEM, WebAccelerator)

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.