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01 Record

CVE-2026-43798

A single crafted SSH message gives an unauthenticated network attacker an out-of-bounds stack write of attacker-controlled length and content against any application built on swift-nio-ssh. This

CriticalPUBLISHEDCNA: apple
CNA base score9.8 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

02 Description

A single crafted SSH message gives an unauthenticated network attacker an out-of-bounds stack write of attacker-controlled length and content against any application built on swift-nio-ssh. This

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
  • Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.47% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 40.4% of scored records. A rank, not a probability.
NVD base score
9.8 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD analysis status
Analyzed. NVD last modified this record on 2026-10-18.
Red Hat severity
No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2026-08-20 21:07Z2 MO AGO
Last updated
2026-08-26 14:05Z2 MO AGO
Reserved
2026-05-01
Assigning CNA
apple
Record state
PUBLISHED
Severity
Critical (CVSS 9.8)
CNA CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weaknesses
  • CWE-121Stack-based Buffer OverflowVariant
Data version
5.2
Document digest
1848acc88ef569f86a19ca5444345e7d91c6aa80981ce2a83f54b14b43c87f90

05 Affected products

VendorProductVersionsPlatforms
Appleswift-nio-ssh0 to < 0.14.1—

06 References