CVE-2023-22486 | cmark-gfm Quadratic complexity bug in handle_close_bracket may lead to a denial of service

Exp

cmark-gfm is GitHub's fork of cmark, a CommonMark parsing and rendering library and program in C. Versions prior to 0.29.0.gfm.7 contain a polynomial time complexity issue in handle_close_bracket that may lead to unbounded resource exhaustion and subsequent denial of service. This vulnerability has been patched in 0.29.0.gfm.7.

Published: 2023-01-26 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-22486 is rated Exploit Available (51.4/100): CVSS Low severity, with medium exploitation likelihood (EPSS 1.11%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2023-22486

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2023-22486

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 2026-06-15 0.18% 1.11% +0.93%
2 2026-06-12 0.09% 0.18% +0.09%
3 2025-11-21 — 0.09% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-22486

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
3.5 3.1 LOW
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
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:L)
A normal user session is enough; they don’t have to be admin.
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:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 2.1 1.4 [email protected]
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-2023-22486

OS Trackers for CVE-2023-22486

vendor priority summary link
alpine high CVE-2023-22486: 1 source package rows (cmark); 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-2023-22486
debian not yet assigned CVE-2023-22486 not yet assigned priority: Debian including 4 source packages (cmark-gfm, python-cmarkgfm, r-cran-commonmark, ruby-commonmarker), 20 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 12, open 8. https://security-tracker.debian.org/tracker/CVE-2023-22486
suse medium — https://www.suse.com/security/cve/CVE-2023-22486/
ubuntu medium CVE-2023-22486 medium priority: Ubuntu including 2 source packages (cmark, cmark-gfm), 26 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 12, needs-triage 6, released 5, not-affected 2, DNE 1. https://ubuntu.com/security/CVE-2023-22486

Affected software / configurations for CVE-2023-22486

Vendor Product Version Raw CPE
github cmark-gfm < 0.29.0.gfm.7 cpe:2.3:a:github:cmark-gfm:*:*:*:*:*:*:*:*

References for CVE-2023-22486

cvelogic Threat Intelligence