CVE-2022-34749

In mistune through 2.0.2, support of inline markup is implemented by using regular expressions that can involve a high amount of backtracking on certain edge cases. This behavior is commonly named catastrophic backtracking.

Published: 2022-07-25 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-34749 is rated Moderate Risk (52.8/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.49%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2022-34749

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 0.43% 0.49% +0.06%
2 2025-11-18 0.52% 0.43% -0.08%
3 2025-10-09 — 0.52% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-34749

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2022-34749

GitHub Security Advisory for CVE-2022-34749

GHSA-fw3v-x4f2-v673 · Severity: high · Ecosystem: pip — Mistune vulnerable to catastrophic backtracking

OS Trackers for CVE-2022-34749

vendor priority summary link
alpine high CVE-2022-34749: 1 source package rows (py3-mistune); 7 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 7, open 0. https://security.alpinelinux.org/vuln/CVE-2022-34749
debian not yet assigned CVE-2022-34749 not yet assigned priority: Debian including 1 source packages (mistune), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2022-34749
redhat medium — https://access.redhat.com/security/cve/CVE-2022-34749
ubuntu medium CVE-2022-34749 medium priority: Ubuntu including 1 source packages (mistune), 13 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 6, needs-triage 4, DNE 1, ignored 1, released 1. https://ubuntu.com/security/CVE-2022-34749

Affected software / configurations for CVE-2022-34749

Vendor Product Version Raw CPE
mistune_project mistune <= 2.0.2 cpe:2.3:a:mistune_project:mistune:*:*:*:*:*:*:*:*
fedoraproject fedora 37 cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:*

References for CVE-2022-34749

cvelogic Threat Intelligence