CWE-42: Path Equivalence: 'filename.' (Trailing Dot)
The product accepts path input in the form of trailing dot ('filedir.') without appropriate validation, which can lead to ambiguous path resolution and allow an attacker to traverse the file system to unintended locations or access arbitrary files.
Last updated
Overview
CWE-42 (Path Equivalence: 'filename.' (Trailing Dot)) is a variant-level software weakness catalogued by MITRE in the Common Weakness Enumeration (CWE). It describes a recurring type of mistake that can lead to exploitable security vulnerabilities.
Real-world CVEs
1 recorded CVEs are caused by CWE-42 (Path Equivalence: 'filename.' (Trailing Dot)). The highest-severity and most recent are shown first. 1 new CWE-42 CVE has been recorded so far in 2026.
Common consequences
What can happen when CWE-42 is exploited.
Bypass Protection Mechanism
Affects: Access Control
How it happens
When it is introduced
Typically introduced during these phases of the software lifecycle.
Illustrative examples
Real CVEs that MITRE cites as examples of this weakness.
- CVE-2000-1114 — Source code disclosure using trailing dot
- CVE-2002-1986 — Source code disclosure using trailing dot
- CVE-2004-2213 — Source code disclosure using trailing dot
- CVE-2005-3293 — Source code disclosure using trailing dot
- CVE-2004-0061 — Bypass directory access restrictions using trailing dot in URL
- CVE-2000-1133 — Bypass directory access restrictions using trailing dot in URL
- CVE-2001-1386 — Bypass check for ".lnk" extension using ".lnk."
Terminology & mappings
Mapped taxonomies
- PLOVER: Trailing Dot - 'filedir.'
- Software Fault Patterns: Path Traversal (SFP16)
Frequently asked questions
Common questions about CWE-42.
- What is CWE-42?
- The product accepts path input in the form of trailing dot ('filedir.') without appropriate validation, which can lead to ambiguous path resolution and allow an attacker to traverse the file system to unintended locations or access arbitrary files.
- What CVEs are caused by CWE-42?
- 1 recorded CVEs are attributed to CWE-42, including CVE-2026-52884.
- What are the consequences of CWE-42?
- Exploiting CWE-42 can lead to: Bypass Protection Mechanism.
- Is CWE-42 actively exploited?
- 1 recorded CVEs are caused by CWE-42; none are currently in CISA's KEV catalog of actively exploited flaws.
References
- MITRE CWE definition (CWE-42) (opens in a new tab)
- CWE-42 vulnerabilities on NVD (opens in a new tab)
- Learn: What is a CWE?
Weakness data is sourced from the MITRE CWE catalog (v4.20). CVE associations are aggregated and kept current by RadicalNotion.AI.
Stay ahead of CWE-42
Get alerted the moment a new CWE-42 vulnerability affects your stack, with AI-written analysis, severity context, and remediation guidance.