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Fencer Vulns
medium 5.3

CVE-2023-28626 json

Quadratic runtime when parsing Markdown in comrak

published 2023-03-28 3 y ago modified 2026-06-17 4 mo ago also GHSA-8hqf-xjwp-p67v , EUVD-2023-0947

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.1%
EPSS 1.1% chance of exploitation in 30 days, percentile 66%
public exploits
0
none known

Summary

comrak is a CommonMark + GFM compatible Markdown parser and renderer written in rust. A range of quadratic parsing issues are present in Comrak. These can be used to craft denial-of-service attacks on services that use Comrak to parse Markdown. This issue has been addressed in version 0.17.0. Users are advised to upgrade. There are no known workarounds for this vulnerability. This issue is also tracked as `GHSL-2023-047`

Patch / fix

  • crates.io comrak 0.17.0
  • comrak_project comrak 0.17.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-28626 updated cvss 5.3

rust-comrak: quadratic runtime when parsing Markdown

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
20 mo ago

Exploit prediction

1.12% chance of exploitation in the next 30 days, higher than 66% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected packages

ecosystem package affected fixed in
crates.io comrak
<0.17.0
0.17.0

Affected products

  • kivikakk comrak

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.