CVE-2026-66486

Terminal output manipulation via unescaped member names

Published Aug 10, 2026 · Updated Aug 10, 2026

Improper output encoding in GNU cpio 2.15 and earlier allows attackers to forge archive listings or inject terminal control sequences. The copy-in listing path prints attacker-controlled member names directly, without quoting or escaping embedded newlines and ANSI escape bytes. Exploitation requires a user to list an attacker-supplied archive; reported effects are limited to misleading or manipulating terminal output.

CVSS severity6.1
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper output encoding in GNU cpio 2.15 and earlier allows attackers to forge archive listings or inject terminal control sequences. The copy-in listing path prints attacker-controlled member names directly, without quoting or escaping embedded newlines and ANSI escape bytes. Exploitation requires a user to list an attacker-supplied archive; reported effects are limited to misleading or manipulating terminal output.

The record

CVE
CVE-2026-66486
Published
Aug 10, 2026
Updated
Aug 10, 2026
Vendor
The GnuPG Project
Product
GNU cpio
Classifications
CWE-116, CWE-94
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=2.15

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The GnuPG Project · GNU cpioversion=0 <=2.15

Published CVSS scores

3.3Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
3.3SUSECVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
6.1Red HatCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-116Improper Encoding or Escaping of Output
CWE-94Improper Control of Generation of Code ('Code Injection')

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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