CWE-135Base

Incorrect Calculation of Multi-Byte String Length

Draft in the CWE catalog · 2 CVEs mapped

2
CVEs mapped
5.9
Median CVSS
What it is

The product does not correctly calculate the length of strings that can contain wide or multi-byte characters.

Recent examples
4.8cvss
CVE-2026-34831

Rack: Content-Length mismatch in Rack::Files error responses

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Files#fail sets the Content-Length response header using String#size instead of String#bytesize. When the response body contains multibyte UTF-8 characters, the declared Content-Length is smaller than the number of bytes actually sent on the wire. Because Rack::Files reflects the requested path in 404 responses, an attacker can trigger this mismatch by requesting a non-existent path containing percent-encoded UTF-8 characters. This results in incorrect HTTP response framing and may cause response desynchronization in deployments that rely on the incorrect Content-Length value. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.

MEDIUMno explanation yet
0%
epss
7.1cvss
CVE-2026-0810

Gix-date: gix-date: undefined behavior due to invalid string generation

A flaw was found in gix-date. The `gix_date::parse::TimeBuf::as_str` function can generate strings containing invalid non-UTF8 characters. This issue violates the internal safety invariants of the `TimeBuf` component, leading to undefined behavior when these malformed strings are subsequently processed. This could potentially result in application instability or other unforeseen consequences.

HIGHno explanation yet
0%
epss
The record
Technical detail
CWE ID
CWE-135
Abstraction
Base
Structure
Simple
Status
Draft
References (2)