# CVE-2026-103022: Urwid: handle_short_request() crashes on non-ASCII POST body (UnicodeEncodeError DoS)

Status: published. Published: 2026-11-06. Updated: 2026-11-06.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- urwid / urwid: < 4.0.7 (affected). Source: CNA: GitHub_M

## Severity and prioritization

- CVSS 3.1: 5.3 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L; source: CNA: GitHub_M

- CVSS 3.1: 5.3 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L; source: NVD: security-advisories@github.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-116, CWE-248, CWE-775

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/urwid/urwid/security/advisories/GHSA-cp25-j9x5-p5xm (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/urwid/urwid/pull/1201 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/urwid/urwid/commit/b79d9a96843a6f5950bb2bfab5d059bdc61c538b (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/urwid/urwid/releases/tag/4.0.7 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/urwid/urwid/commit/b79d9a96843a6f5950bb2bfab5d059bdc61c538b (security-advisories@github.com)

- https://github.com/urwid/urwid/pull/1201 (security-advisories@github.com)

- https://github.com/urwid/urwid/releases/tag/4.0.7 (security-advisories@github.com)

- https://github.com/urwid/urwid/security/advisories/GHSA-cp25-j9x5-p5xm (security-advisories@github.com)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-103022; retrieved 2026-11-06; source updated 2026-11-06

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-103022; retrieved 2026-11-07; source updated 2026-11-06

Revision: 8d2d9364c8a7a4a95af6f276f06eee8370481416f21d8ae7e5346a7816248852

Canonical: https://y2.dev/cve/CVE-2026-103022

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