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Fencer Vulns
medium 6.5

CVE-2026-20657 json

A buffer overflow issue was addressed with improved memory handling.

published 2026-03-25 7 mo ago modified 2026-10-26 13 d ago also EUVD-2026-15047

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 46%
public exploits
0
none known

Summary

A buffer overflow issue was addressed with improved memory handling. This issue is fixed in iOS 18.7.7 and iPadOS 18.7.7, iOS 26.4 and iPadOS 26.4, macOS Sequoia 15.7.5, macOS Sonoma 14.8.5, macOS Tahoe 26.4, visionOS 26.4. Parsing a maliciously crafted file may lead to an unexpected app termination.

Patch / fix

  • Apple iOS and iPadOS 18.7.7, 26.4
  • Apple macOS 14.8.5, 15.7.5, 26.4
  • Apple visionOS 26.4

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

0.56% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Affected products

  • Apple iOS and iPadOS
  • Apple macOS
  • Apple visionOS

Classification

Weakness
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
  • CWE-125 Out-of-bounds Read
  • CWE-787 Out-of-bounds Write

References

Sources

Fencer Vulns 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.