Dash: dash: super-polynomial backtracking in pmatch when libc fnmatch is disabled
Summary
| CVE | CVE-2026-102473 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-29 10:17:10 UTC |
| Updated | 2026-09-30 21:17:04 UTC |
| Description | A flaw was found in dash. When built without libc fnmatch, the internal pmatch() matcher implements * by unbounded recursion over candidate positions. A local user who can plant filenames, or otherwise feed that matcher, can make a short multi-star pattern such as *.*.*.*.*.tar.gz consume excessive CPU. |
Risk And Classification
Primary CVSS: v3.1 5.5 MEDIUM from [email protected]
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.001300000 probability, percentile 0.022040000 (date 2026-09-29)
Problem Types: CWE-1333 | CWE-1333 Inefficient Regular Expression Complexity
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 5.5 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | CVSS | 5.5 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Enterprise Linux 6 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/security/cve/CVE-2026-102473 | [email protected] | access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Red Hat would like to thank Shubham Raj (Causal Security) for reporting this issue. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-09-29T08:34:06.065Z | Reported to Red Hat. |
| CNA | 2026-09-29T00:00:00.000Z | Made public. |
Workarounds
CNA: Rebuild dash with --enable-fnmatch so pathname matching uses libc fnmatch. Until then, do not run dash globs, case, or ${var#pat} / ${var%pat} against attacker-controlled names with multi-star patterns. There is no upstream backtracking bound in the internal matcher.
There are currently no legacy QID mappings associated with this CVE.