CVE-2026-102474: Dash: dash: heap out-of-bounds write in conv_escape via undersized unicode escape reservation
Published Sep 29, 2026
·Updated
A flaw was found in dash. The printf builtin reserves four bytes before converting a Unicode \u or \U escape, but the multi-byte token can need five or six bytes. A local user who can supply such an escape to dash printf or echo %b, including through dash -c and a positional argument, can write one or two bytes past that reservation.
Affected Software
1 affected component
Dash dash
Event History
Sep 29, 2026
Data Sourced
via Red Hat·08:34 AM
DescriptionSeverityAffected Software
CVE Published
via MITRE·09:23 AM
Data Sourced
via MITRE·09:23 AM
DescriptionSeverityWeakness
Data Sourced
via NVD·10:17 AM
DescriptionSeverityWeakness
Frequently Asked Questions
1
What input paths can trigger the overflow?
The issue can be triggered when dash processes a Unicode \u or \U escape through its printf builtin or through echo %b. The supplied input may also reach dash via dash -c and a positional argument.
2
What level of access does an attacker need?
An attacker needs local ability to supply a crafted Unicode escape to a dash invocation. The provided data does not indicate that privileges, user interaction, or network access are required.