CVE-2026-105240
Improper Neutralization of Null Byte or NUL Character vulnerability in the…
- Risk score
- 43/100
- CVSS
- 5.3 v3.1
- Exploit chance (30 days)
- 0.8%
- Published
- 6 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- Improper Neutralization of Null Byte or NUL Character vulnerability in the OutputDebugStringAppender of Apache log4net. A NUL character in logged content ended the debug output record at that point, so everything the layout rendered after it, including exception text and trailing fields, was silently lost. A party who…
- Affected
- Apache log4net before 3.5.0
- Fix
- Upgrade Apache log4net to 3.5.0 or later.
- Exploitation
- No known exploitation
Why it is Yellow
- CVSS 5.3 medium
References
Original description
Improper Neutralization of Null Byte or NUL Character vulnerability in the OutputDebugStringAppender of Apache log4net. A NUL character in logged content ended the debug output record at that point, so everything the layout rendered after it, including exception text and trailing fields, was silently lost. A party whose data reaches a log message could hide the rest of that record. Only applications on Windows that use OutputDebugStringAppender are affected. This issue affects Apache log4net: from 1.2.9 before 3.5.0. Users are recommended to upgrade to version 3.5.0, which fixes the issue.
Last activity 6 Oct 2026. Patch Forecast updates every hour.