Distribution advisory
This page covers CVE-2023-26303 as tracked by PyPI (Root.io), for the package markdown-it-py. The fix is available in version 2.1.0+aikido.5; earlier versions remain affected.
How this vulnerability can be exploited
This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.
CVSS metrics in full
The score comes from this vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Attack vector: Local — a local account, shell or session on the host is needed.
- Attack complexity: Low — the attack works reliably, with no preparation.
- Privileges required: Low — an ordinary user account is enough.
- User interaction: None — nobody has to be tricked into anything.
- Scope: Unchanged — the damage stays inside the vulnerable component.
- Confidentiality impact: None.
- Integrity impact: None.
- Availability impact: High — total loss, or loss the attacker controls.
Weakness class
ROOT-APP-PYPI-CVE-2023-26303 is classified as CWE-173: Improper Handling of Alternate Encoding. The product does not properly handle when an input uses an alternate encoding that is valid for the control sphere to which the input is being sent.
Affected software
ROOT-APP-PYPI-CVE-2023-26303 is recorded against 2 packages.
- markdown-it-py (fixed in 2.1.0+aikido.5)
- rootio-markdown-it-py (fixed in 2.1.0+root.io.5)
Timeline and source
Published on 3 June 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.
Other advisories for this package
markdown-it-py has other advisories on record. If you are patching this one, these are worth checking on the same host:
Same weakness in other software
These advisories are the same class of weakness (CWE-173: Improper Handling of Alternate Encoding) in other software:
