# CVE-2026-9323: python-urwid: The urwid web display backend (urwid/display/web.py) generates web session identifiers (urwid_id) in Screen.start() b... CVE-2026-9323 is fixed in 5 products on 1 platform, first by python-urwid 2.0.1-2ubuntu0.1~esm1, released July 18, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-9323 - Priority: High - CVSS: 8.1 (important) - EPSS: 0.0072 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Jul 18, 2026 ## Description The urwid web display backend (urwid/display/web.py) generates web session identifiers (urwid_id) in Screen.start() by concatenating two random.randrange(10**9) calls that use Python's Mersenne Twister PRNG, which is not cryptographically secure. Each call consumes approximately 30 bits of PRNG state, and the Mersenne Twister internal state is approximately 19,937 bits, so an attacker who observes approximately 334 session IDs (for example via the X-Urwid-ID HTTP response header) can fully reconstruct the internal state and predict all past and future session IDs (Path B). The same identifier is also used as the filename of a FIFO created in the world-listable /tmp directory (for example /tmp/urwid375487765176907690.in), so any local user on the host can list /tmp to enumerate active session tokens directly (Path A). With a valid session ID, an attacker can read the victim's terminal screen via the polling endpoint, inject keystrokes into the victim's session (yielding OS-level code execution with the session owner's privileges if the session runs a shell), and inject exit sequences or flood the FIFO to terminate or crash the session. A prior Bandit S311 warning on this usage was suppressed with # noqa: S311 rather than fixed ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | python-urwid RHEL 10 | 2.5.3-4.el10_0.5 | [RHSA-2026:60353](https://patchblox.com/security/data/fix/linux/rhsa-2026-60353.md) | Jul 18, 2026 | | Linux | python-urwid Ubuntu 18.04.6 LTS (bionic) | 2.0.1-2ubuntu0.1~esm1 | [python-urwid 2.0.1-2ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python-urwid-2.0.1-2ubuntu0.1-esm1.md) | Jul 18, 2026 | | Linux | python-urwid rocky 10 | 0:2.5.3-4.el10_2.5 | [RLSA-2026:58561](https://patchblox.com/security/data/fix/linux/rlsa-2026-58561.md) | Aug 24, 2026 | | Linux | python-urwid rocky 8 | 0:1.3.1-5.el8_10 | [RLSA-2026:58562](https://patchblox.com/security/data/fix/linux/rlsa-2026-58562.md) | Aug 24, 2026 | | Linux | python-urwid rocky 9 | 0:2.1.2-4.el9_8.1 | [RLSA-2026:58952](https://patchblox.com/security/data/fix/linux/rlsa-2026-58952.md) | Aug 25, 2026 | | Linux | python-urwid sles 15.6 | 2.0.1-150000.3.3.1 | [SUSE-SU-2026:3460-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3460-1.md) | Aug 3, 2026 | | Linux | python-urwid sles 15.7 | 2.0.1-150000.3.3.1 | [SUSE-SU-2026:3460-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3460-1.md) | Aug 3, 2026 | | Linux | python-urwid-debugsource amzn 2023 | 2.1.2-5.amzn2023.0.1 | [ALAS2023-2026-2049](https://patchblox.com/security/data/fix/linux/alas2023-2026-2049.md) | Aug 17, 2026 | | Linux | python3-urwid RHEL 8 | 0:1.3.1-5.el8_10 | [RHSA-2026:58562](https://patchblox.com/security/data/fix/linux/rhsa-2026-58562.md) | Aug 28, 2026 | | Linux | python3-urwid RHEL 9 | 0:2.1.2-4.el9_8.1 | [RHSA-2026:58952](https://patchblox.com/security/data/fix/linux/rhsa-2026-58952.md) | Aug 28, 2026 | | Linux | python3-urwid Ubuntu 18.04.6 LTS (bionic) | 2.0.1-2ubuntu0.1~esm1 | [python3-urwid 2.0.1-2ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python3-urwid-2.0.1-2ubuntu0.1-esm1.md) | Jul 18, 2026 | | Linux | python3-urwid Ubuntu 20.04 LTS (focal) | 2.0.1-3ubuntu0.1~esm1 | [python3-urwid 2.0.1-3ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-python3-urwid-2.0.1-3ubuntu0.1-esm1.md) | Jul 18, 2026 | | Linux | python3-urwid Ubuntu 22.04.1 LTS (jammy) | 2.1.2-2ubuntu0.1 | [python3-urwid 2.1.2-2ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-python3-urwid-2.1.2-2ubuntu0.1.md) | Jul 18, 2026 | | Linux | python3-urwid Ubuntu 26.04.1 LTS (resolute) | 3.0.4-1ubuntu0.1~esm1 | [python3-urwid 3.0.4-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-python3-urwid-3.0.4-1ubuntu0.1-esm1.md) | Jul 18, 2026 | | Linux | python3-urwid almalinux 10 | 2.5.3-4.el10_2.5 | [ALSA-2026:58561](https://patchblox.com/security/data/fix/linux/alsa-2026-58561.md) | Aug 24, 2026 | | Linux | python3-urwid almalinux 8 | 1.3.1-5.el8_10 | [ALSA-2026:58562](https://patchblox.com/security/data/fix/linux/alsa-2026-58562.md) | Aug 24, 2026 | | Linux | python3-urwid almalinux 9 | 2.1.2-4.el9_8.1 | [ALSA-2026:58952](https://patchblox.com/security/data/fix/linux/alsa-2026-58952.md) | Aug 24, 2026 | | Linux | python3-urwid amzn 2023 | 2.1.2-5.amzn2023.0.1 | [ALAS2023-2026-2049](https://patchblox.com/security/data/fix/linux/alas2023-2026-2049.md) | Aug 17, 2026 | | Linux | python3-urwid ol 10 | 0:2.5.3-4.el10_2.5 | [ELSA-2026-58561](https://patchblox.com/security/data/fix/linux/elsa-2026-58561.md) | Aug 24, 2026 | | Linux | python3-urwid ol 8 | 0:1.3.1-5.el8_10 | [ELSA-2026-58562](https://patchblox.com/security/data/fix/linux/elsa-2026-58562.md) | Aug 24, 2026 | | Linux | python3-urwid ol 9 | 0:2.1.2-4.el9_8.1 | [ELSA-2026-58952](https://patchblox.com/security/data/fix/linux/elsa-2026-58952.md) | Aug 24, 2026 | | Linux | python3-urwid-debuginfo amzn 2023 | 2.1.2-5.amzn2023.0.1 | [ALAS2023-2026-2049](https://patchblox.com/security/data/fix/linux/alas2023-2026-2049.md) | Aug 17, 2026 | | Linux | urwid Debian 12.15 (bookworm) | 2.1.2-4+deb12u1 | [DEBIAN-CVE-2026-9323](https://patchblox.com/security/data/fix/linux/debian-cve-2026-9323.md) | Jul 18, 2026 | | Linux | urwid Debian 14 | 4.1.3-1 | [DEBIAN-CVE-2026-9323](https://patchblox.com/security/data/fix/linux/debian-cve-2026-9323.md) | Jul 18, 2026 | --- Data as of 2026-11-08T06:59:42Z UTC. 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