Urwid: handle_short_request() crashes on non-ASCII POST body (UnicodeEncodeError DoS)
- Exploited
- No known exploitation
- Fix
- Fixed in 4.0.7
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 4.0.7.
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 22/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
Urwid, a Python console user interface library, has a flaw in its web display interface that lets an attacker remotely, without logging in, crash request handling with non-ASCII POST data or non-UTF-8 polling output. Repeated requests can also leak file descriptors, causing a denial of service for the web display interface.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
Urwid is a console user interface library for Python. Prior to 4.0.7, handle_short_request() in urwid/display/web.py performs unguarded character encoding on POST input and unguarded UTF-8 decoding on polling update socket output. A remote attacker who obtains a valid X-Urwid-ID session token can submit non-ASCII POST data that raises UnicodeEncodeError, while non-UTF-8 polling output raises UnicodeDecodeError, causing the CGI handler to return an error and terminate request processing. The POST exception path also leaves an opened file descriptor unclosed for the CGI process lifetime, so repeated requests can cause denial of service for the web display interface. This issue is fixed in version 4.0.7.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure17/25No login or user action needed per the CVSS vector, reachable over the network without a login · Unknown: No advisory context yet
- Reach?/20Unknown. No tracked technology or package matched
- Severity5.3/10CVSS 5.3
- No patch0/5No signal
What would change the score
- Would score about 67 if added to CISA KEV
- Would score about 62 if CISA's SSVC rates exploitation active
- Would score about 27 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 4.0.7.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- urwid urwid
fixed in 4.0.7
Evidence 4
- Advisory
- Repository
- Repository
- Repository
Corrections
None so far.
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Questions about CVE-2026-103022
Is CVE-2026-103022 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-103022?
urwid: before 4.0.7.Source: cve.now feed data
How do I fix CVE-2026-103022?
Upgrade to a fixed version: 4.0.7.Source: cve.now feed data