Back to the CVE list
CVE-2026-118694

python-markdown2 through 2.5.5 Denial of Service via Unclosed Inline Link Destinations

CVSS score

8.7

EPSS probability

—

Risk score

0.9

Published

2 h ago

OverviewPublic Exploits (0)NewsroomVulnerability Timeline
Official patch verified

Etkilenen ürün ve sürüm için yayımlanan güvenlik güncellemesini uygulayın.

Impact on My Inventory

Only the personal products you have added to your account are assessed; an organisation's inventory does not appear here.

Checking session…

Vulnerability description

DayBreach AI Explanation

Verified against sources

Denial of Service Vulnerability in python-markdown2

Sources read

1

Source agreement

Tam uyum

Evidence confidence

%55

Short explanation

python-markdown2 through version 2.5.5 contains a denial of service vulnerability that allows remote users to exhaust CPU by submitting Markdown with unclosed inline link destinations.

Why does it matter?

This vulnerability enables remote users to exhaust CPU resources via submitted inputs and cause service disruptions.

What should be done?

  • Review the provided patch references
  • Follow vendor advisories
  • Apply the relevant pull requests
Chain of evidence and sources2 verified claims

python-markdown2 2.5.5 ve önceki sürümleri, kapatılmamış bağlantı hedefleri nedeniyle bir denial of service zafiyeti içermektedir.

S0 · daybreach-canonicalS1 · cvelist

Saldırganlar tekrar eden diziler göndererek _find_balanced fonksiyonunun kuadratik CPU süresi tüketmesine neden olabilir.

S0 · daybreach-canonicalS1 · cvelist
Show the technical text from the sources

python-markdown2 through 2.5.5 contains a denial of service vulnerability that allows remote users to exhaust CPU by submitting Markdown with unclosed inline link destinations. Attackers can submit repeated '[a](' or '![a](' sequences, causing _find_balanced to rescan the remaining document for each link and consume quadratic CPU time.

CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CWE: CWE-407

This explanation was compiled automatically from the source records. Scores, active exploitation, patch and exploit status come straight from the sources.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-118694 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

IDVENDORPRODUCTACTION
1trentmpython-markdown2 View
Total affected vendors: 1|Products: 1

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCOREVERSIONSEVERITYVECTORSOURCE
8.7CVSS V40HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XNVD
8.7CVSS V4_0HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NCVE CNA
7.5CVSS V31HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HNVD
7.5CVSS V3_1HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVE CNA

Patch and Remediation Guide

Solution & Remediation Advisory

Patch verified

2 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

cvelist

CNA çözüm referansı

Open source
reference

Yama veya çözüm referansı

Open source
Confirm the affected product and version against the source evidence above.
Restrict access to internet-facing services and apply network segmentation.
Apply the official update named in the evidence only to the matching product and version.
Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-118694 is associated with the following CWEs:

CWE-407: Common Weakness Enumeration Entry CWE-407

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-118694 weaknesses.

CAPEC-66: SQL InjectionCAPEC-126: Path TraversalCAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden
PermissionsGerekmiyor
UserGerekmiyor

Official Sources and Advisories

GitHub Issue #750vendor-advisoryhttps://github.com/trentm/python-markdown2vendor-advisoryhttps://github.com/trentm/python-markdown2/blob/2.5.5/lib/markdown2.py#L1478-L1492vendor-advisoryhttps://github.com/trentm/python-markdown2/blob/2.5.5/lib/markdown2.py#L3029vendor-advisoryhttps://github.com/trentm/python-markdown2/pull/751patchVulnCheck Advisory: python-markdown2 through 2.5.5 Denial of Service via Unclosed Inline Link Destinationsvendor-advisory

CVSS Vector Radar Chart

8.7 / 10
Attack VectorNetworkComplexityLowPrivilegesNoneUser Interact.NoneConfidentialityLowIntegrityNoneAvailabilityHigh

Vulnerability Scoring Details

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone required
User InteractionNone required
Confidentiality (Gizlilik)Low
Integrity (Bütünlük)None
Availability (Erişilebilirlik)High

Yama doğrulandı

2 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

Follow the vendor

T
trentm logo
trentm

Weakness Type (CWE & CAPEC)

CWE-407

Get this vulnerability through the API

Affected products, version ranges, exploitation status and patch information in a single request, with a free key.

Get a free keyDocumentation
curl -H "x-api-key: $DAYBREACH_API_KEY" \
  "https://api.daybreach.dev/api/v1/intel/cves/CVE-2026-118694"
CVE-2026-118694 · python-markdown2 through 2.5.5 Denial of…