Vulnerabilities

Vulnerability · CVE-2026-88753

A Regular-Expression Denial of Service (ReDoS) in the Markdown2.

Published Oct 15, 2026 · catalog updated Oct 16, 2026 · A Regular-Expression Denial of

Check if you run it

No confirmed exploitation is on record for CVE-2026-88753. EPSS is 0.15%. Act only if a listed version of A Regular-Expression Denial of is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (A Regular-Expression Denial of).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Unknown—
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.15%
Remediation
Advisory link
Affected products
Debian:12 python-markdown2 · Debian:13 python-markdown2 · Debian:14 python-markdown2 · vendor n/a n/a

A Regular-Expression Denial of Service (ReDoS) in the Markdown2. extract_metadata() function (lib/markdown2.py) of trentm markdown2 through v2.5.5 allows attackers to cause a Denial of Service (DoS) via a crafted Markdown document.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • Debian:12 python-markdown22.4.1-1, 2.4.11-1, 2.5.3-1~exp1
  • Debian:13 python-markdown22.4.11-1, 2.5.3-1~exp1, 2.5.4-1
  • Debian:14 python-markdown22.4.11-1, 2.5.3-1~exp1, 2.5.4-1
  • vendor n/a n/aversion unspecified

How to fix CVE-2026-88753

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-88753. EPSS is 0.15%. Act only if a listed version of A Regular-Expression Denial of is installed.

Which versions are affected?

Compare what you have installed with 2.4.1-1, 2.4.11-1, 2.5.3-1~exp1, 2.4.11-1, 2.5.3-1~exp1, 2.5.4-1. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.15%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 15, 2026 · NIST NVD

    Detected

    A Regular-Expression Denial of Service (ReDoS) in the Markdown2. extract_metadata() function (lib/markdown2.py) of trentm markdown2 through v2.5.5 allows attackers to cause a Denial of Service (DoS) via a crafted Markdown document.

  2. Oct 16, 2026 · OpenSSF OSV / OSV Scanner

    Updated

    A Regular-Expression Denial of Service (ReDoS) in the Markdown2. extract_metadata() function (lib/markdown2.py) of trentm markdown2 through v2.5.5 allows attackers to cause a Denial of Service (DoS) via a crafted Markdown document.

Sources

  • CVE.orgVulnerability recordCVE-2026-88753

    A Regular-Expression Denial of Service (ReDoS) in the Markdown2. extract_metadata() function (lib/markdown2.py) of trentm markdown2 through v2.5.5 allows attackers to cause a Denial of Service (DoS) via a crafted Markdown document.

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-88753

    30-day exploitation probability 0.1%

    first.org
  • NIST NVDVulnerability recordCVE-2026-88753

    A Regular-Expression Denial of Service (ReDoS) in the Markdown2. extract_metadata() function (lib/markdown2.py) of trentm markdown2 through v2.5.5 allows attackers to cause a Denial of Service (DoS) via a crafted Markdown document.

    nvd.nist.gov
  • OpenSSF OSV / OSV ScannerPackage advisoryDEBIAN-CVE-2026-88753
    osv.dev

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.