CVE-2018-5773
markdown2 is vulnerable to cross-site scripting
CVE-2018-5773 is a medium vulnerability (CVSS 6.1) in Python-markdown2 Project Python-markdown2, published January 18, 2018. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.82%, the 57th percentile. Fixed in markdown2 2.3.6.
An issue was discovered in markdown2 (aka python-markdown2) through 2.3.5. The safe_mode feature, which is supposed to sanitize user input against XSS, is flawed and does not escape the input properly. With a crafted payload, XSS can be triggered, as demonstrated by omitting the final '>' character from an IMG tag.
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
NVD Score used
An issue was discovered in markdown2 (aka python-markdown2) through 2.3.5. The safe_mode feature, which is supposed to sanitize user input against XSS, is flawed and does not escape the input properly. With a crafted payload, XSS can be triggered, as demonstrated by omitting the final '>' character from an IMG tag.
- Record
CVE-2018-5773- 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
CVE List No score
An issue was discovered in markdown2 (aka python-markdown2) through 2.3.5. The safe_mode feature, which is supposed to sanitize user input against XSS, is flawed and does not escape the input properly. With a crafted payload, XSS can be triggered, as demonstrated by omitting the final '>' character from an IMG tag.
- Record
CVE-2018-5773- Updated
- 2026-11-02
EUVDEUVD-2018-0089 No score
An issue was discovered in markdown2 (aka python-markdown2) through 2.3.5. The safe_mode feature, which is supposed to sanitize user input against XSS, is flawed and does not escape the input properly. With a crafted payload, XSS can be triggered, as demonstrated by omitting the final '>' character from an IMG tag.
- Record
EUVD-2018-0089- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-p6h9-gw49-rqm4
markdown2 is vulnerable to cross-site scripting
An issue was discovered in markdown2 (aka python-markdown2) through 2.3.5. The safe_mode feature, which is supposed to sanitize user input against XSS, is flawed and does not escape the input properly. With a crafted payload, XSS can be triggered, as demonstrated by omitting the final > character from an IMG tag.
- Record
GHSA-p6h9-gw49-rqm4- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA: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 - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
An issue was discovered in markdown2 (aka python-markdown2) through 2.3.5. The safe_mode feature, which is supposed to sanitize user input against XSS, is flawed and does not escape the input properly. With a crafted payload, XSS can be triggered, as demonstrated by omitting the final '>' character from an IMG tag.
- Record
CVE-2018-5773- 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
OSVGHSA-p6h9-gw49-rqm4
markdown2 is vulnerable to cross-site scripting
An issue was discovered in markdown2 (aka python-markdown2) through 2.3.5. The safe_mode feature, which is supposed to sanitize user input against XSS, is flawed and does not escape the input properly. With a crafted payload, XSS can be triggered, as demonstrated by omitting the final > character from an IMG tag.
- Record
GHSA-p6h9-gw49-rqm4- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA: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 - Weakness
- CWE-79
- Updated
- 2026-11-02
Show 4 moreShow less
OSVopenSUSE-SU-2024:11237-1 No score
python36-markdown2-2.4.0-2.4 on GA media
These are all security issues fixed in the python36-markdown2-2.4.0-2.4 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:11237-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:14146-1 No score
python310-markdown2-2.4.13-1.2 on GA media
These are all security issues fixed in the python310-markdown2-2.4.13-1.2 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:14146-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2026:12016-1 No score
python313-markdown2-2.5.5-1.3 on GA media
These are all security issues fixed in the python313-markdown2-2.5.5-1.3 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:12016-1- Updated
- 2026-11-02
OSVPYSEC-2018-13 No score
An issue was discovered in markdown2 (aka python-markdown2) through 2.3.5. The safe_mode feature, which is supposed to sanitize user input against XSS, is flawed and does not escape the input properly. With a crafted payload, XSS can be triggered, as demonstrated by omitting the final '>' character from an IMG tag.
- Record
PYSEC-2018-13- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
markdown2PyPI |
before 2.3.6 | 2.3.6 |
markdown2PyPI |
before 2.3.6, plus listed versions 1.0.1.101.0.1.111.0.1.121.0.1.131.0.1.14 Show 30 moreShow less1.0.1.151.0.1.161.0.1.171.0.1.181.0.1.191.0.1.61.0.1.71.0.1.81.0.1.91.1.01.1.11.2.01.3.01.3.11.4.01.4.11.4.22.0.02.0.12.1.02.2.02.2.12.2.22.2.32.3.02.3.12.3.22.3.32.3.42.3.5 |
2.3.6 |
python-markdown2openSUSE:Tumbleweed |
before 2.4.0-2.4 | 2.4.0-2.4 |
python-markdown2openSUSE:Tumbleweed |
before 2.4.13-1.2 | 2.4.13-1.2 |
python-markdown2openSUSE:Tumbleweed |
before 2.5.5-1.3 | 2.5.5-1.3 |
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-03 | aliases | EUVD |
| 2026-11-02 | created | CVE List, GitHub Advisories, NVD, OSV |