CVE-2018-1000874
** DISPUTED ** PHP cebe markdown parser version 1.2.0 and earlier contains a Cross Site Scripting...
PHP cebe markdown parser version 1.2.0 and earlier contains a Cross Site Scripting (XSS) vulnerability in all distributed parsers allowing a malicious crafted script to be executed that can result in the lose of user data and sensitive user information. This attack can be exploited by crafting a three backtick wrapped payload with a character in front: L: "<script>alert();</script>". NOTE: This has been argued as a non-issue (see references) since it is not the parser's job to sanitize malicious code from a parsed document
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List
6.1
PHP cebe markdown parser version 1.2.0 and earlier contains a Cross Site Scripting (XSS) vulnerability in all distributed parsers allowing a malicious crafted script to be executed that can result in the lose of user data and sensitive user information. This attack can be exploited by crafting a three backtick wrapped payload with a character in front: L: "<script>alert();</script>". NOTE: This has been argued as a non-issue (see references) since it is not the parser's job to sanitize malicious code from a parsed document
- Record
CVE-2018-1000874- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2018-2051
6.1
PHP cebe markdown parser version 1.2.0 and earlier contains a Cross Site Scripting (XSS) vulnerability in all distributed parsers allowing a malicious crafted script to be executed that can result in the lose of user data and sensitive user information. This attack can be exploited by crafting a three backtick wrapped payload with a character in front: L: "<script>alert();</script>". NOTE: This has been argued as a non-issue (see references) since it is not the parser's job to sanitize malicious code from a parsed document
- Record
EUVD-2018-2051- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-gvg5-fmh4-q8jg
6.1
** DISPUTED ** PHP cebe markdown parser version 1.2.0 and earlier contains a Cross Site Scripting...
** DISPUTED ** PHP cebe markdown parser version 1.2.0 and earlier contains a Cross Site Scripting (XSS) vulnerability in all distributed parsers allowing a malicious crafted script to be executed that can result in the lose of user data and sensitive user information. This attack can be exploited by crafting a three backtick wrapped payload with a character in front: L: "<script>alert();</script>". NOTE: This has been argued as a non-issue (see references) since it is not the parser's job to sanitize malicious code from a parsed document.
- Record
GHSA-gvg5-fmh4-q8jg- CVSS 3.0
- 6.1 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
6.1
PHP cebe markdown parser version 1.2.0 and earlier contains a Cross Site Scripting (XSS) vulnerability in all distributed parsers allowing a malicious crafted script to be executed that can result in the lose of user data and sensitive user information. This attack can be exploited by crafting a three backtick wrapped payload with a character in front: L: "<script>alert();</script>". NOTE: This has been argued as a non-issue (see references) since it is not the parser's job to sanitize malicious code from a parsed document
- Record
CVE-2018-1000874- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - CVSS 3.0
- 6.1 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
6.1
PHP cebe markdown parser version 1.2.0 and earlier contains a Cross Site Scripting (XSS) vulnerability in all distributed parsers allowing a malicious crafted script to be executed that can result in the lose of user data and sensitive user information. This attack can be exploited by crafting a three backtick wrapped payload with a character in front: L: "<script>alert();</script>". NOTE: This has been argued as a non-issue (see references) since it is not the parser's job to sanitize malicious code from a parsed document
- Record
CVE-2018-1000874- CVSS 3.0
- 6.1 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2018-1000874 is a medium vulnerability (CVSS 6.1) in Cebe Markdown, published December 20, 2018. Its validity is disputed. EPSS puts the chance of exploitation in the next 30 days at 0.80%, the 56th percentile.