5.3

CVE-2021-26540: apostrophecms sanitize-html

CVSS: 5.3v3.1MediumModified
AliasesGHSA-mjxr-4v3x-q3m4
Published 08-02-2021Last modified 03-08-2024
Open JSON

Vulnerability summary

CVE-2021-26540 is a medium (CVSS 5.3) vulnerability in apostrophecms sanitize-html. EPSS estimates a 1.75% chance of exploitation in the next 30 days, higher than 77.7% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
32/100
0100
Medium · default modelHow is this calculated?
CVSS score
5.3/10
010
Medium · v3.1 (NVD)
EPSS score
1.75%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1reference

Timeline

  1. 08-02-2021
    PublishedVulnerability first disclosed.
  2. 03-08-2024
    Last modifiedVulnerability information updated.

Description

Apostrophe Technologies sanitize-html before 2.3.2 does not properly validate the hostnames set by the "allowedIframeHostnames" option when the "allowIframeRelativeUrls" is set to true, which allows attackers to bypass hostname whitelist for iframe element, related using an src value that starts with "/\\example.com".

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

1.75%

Chance of exploitation in the next 30 days

Percentile

78%

Versus all other CVEs

30-day change

0.00 pp

From 1.75% on 21-09-2026

21-09-202621-10-2026
EPSS score
1.75%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • referenceUnverified

    Exploit Reference (advisory.checkmarx.net)

    Maturity: unknown

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Apostrophecms1 product
Npm1 product
  • sanitize-html< 2.3.2

2 vendors · 2 products

References

4 links