CVE-2026-66486
Improper Output Encoding in GNU cpio
Description
GNU cpio is vulnerable to improper encoding or escaping of output in its archive member listing functionality. When listing archive members via cpio -it, member names are printed directly to output without quoting or escaping. An attacker can craft a cpio archive containing member names with embedded newline characters or ANSI escape sequences, causing forged listing entries or terminal control sequence injection when the listing is displayed. This issue has been fixed in commit 2ff9600c9ef32e88759843cdbde74c8db5ae9b30
INFO
Published Date :
Aug. 10, 2026, 11:17 a.m.
Last Modified :
Aug. 10, 2026, 11:17 a.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 4.0 | MEDIUM | 4bb8329e-dd38-46c1-aafb-9bf32bcb93c6 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Apply commit 2ff9600c9ef32e88759843cdbde74c8db5ae9b30 to cpio.
- Update to a patched version of GNU cpio.
- Avoid processing untrusted cpio archives.
- Sanitize member names before listing.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-66486.
| URL | Resource |
|---|---|
| https://cert.pl/en/posts/2026/08/CVE-2026-66484 | |
| https://git.savannah.gnu.org/cgit/cpio.git |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-66486 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-66486
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-66486 vulnerability anywhere in the article.
-
cert.pl
Vulnerabilities in GNU cpio software
Vulnerabilities in GNU cpio software CVE ID CVE-2026-66484 Publication date 10 August 2026 Vendor GNU Product cpio Vulnerable versions All through 2.15 Vulnerability type (CWE) Improper Limitation of ... Read more
The following table lists the changes that have been made to the
CVE-2026-66486 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Aug. 10, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.savannah.gnu.org/cgit/cpio.git', 'vendor': 'GNU', 'product': 'cpio', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'custom', 'lessThanOrEqual': '2.15'}], 'programFiles': ['copyin.c'], 'defaultStatus': 'unaffected'}] Added Description GNU cpio is vulnerable to improper encoding or escaping of output in its archive member listing functionality. When listing archive members via cpio -it, member names are printed directly to output without quoting or escaping. An attacker can craft a cpio archive containing member names with embedded newline characters or ANSI escape sequences, causing forged listing entries or terminal control sequence injection when the listing is displayed. This issue has been fixed in commit 2ff9600c9ef32e88759843cdbde74c8db5ae9b30 Added CVSS V4.0 AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/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 Added CWE CWE-116 Added Reference https://cert.pl/en/posts/2026/08/CVE-2026-66484 Added Reference https://git.savannah.gnu.org/cgit/cpio.git -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 10, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-66486', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-10T10:34:59.850493Z'}