CVE-2025-30358 json
Mesop Class Pollution vulnerability leads to DoS and Jailbreak attacks
published last yr. modified 4mo ago also EUVD-2025-14804 , GHSA-f3mf-hm6v-jfhh , PYSEC-2026-1624
- cvss
- 8.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.7%
- EPSS 0.7% chance of exploitation in 30 days, percentile 53%
- public exploits
- 0
- none known
Summary
Mesop is a Python-based UI framework that allows users to build web applications. A class pollution vulnerability in Mesop prior to version 0.14.1 allows attackers to overwrite global variables and class attributes in certain Mesop modules during runtime. This vulnerability could directly lead to a denial of service (DoS) attack against the server. Additionally, it could also result in other severe consequences given the application's implementation, such as identity confusion, where an attacker could impersonate an assistant or system role within conversations. This impersonation could potentially enable jailbreak attacks when interacting with large language models (LLMs). Just like the Javascript's prototype pollution, this vulnerability could leave a way for attackers to manipulate the intended data-flow or control-flow of the application at runtime and lead to severe consequences like remote code execution when gadgets are available. Users should upgrade to version 0.14.1 to obtain a fix for the issue.
Patch / fix
Is CVE-2025-30358 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- last yr.
Exploit prediction
0.71% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H |
| GitHub | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H |
| OSV | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | mesop | <0.14.1 |
0.14.1 |
Affected products
- mesop-dev mesop
Classification
- Weakness
-
- CWE-915 Improperly Controlled Modification of Dynamically-Determined Object Attributes
References
-
github.com
/mesop-dev/mesop/commit/748e20d4a363d89b841d62213f5b0c6b4bed788f
web
-
github.com
/mesop-dev/mesop/security/advisories/GHSA-f3mf-hm6v-jfhh
web
-
nvd.nist.gov
/vuln/detail/CVE-2025-30358
advisory
-
github.com
/mesop-dev/mesop
package
-
pypi.org
/project/mesop
package
-
github.com
/advisories/GHSA-f3mf-hm6v-jfhh
advisory
Sources
- CVE List CVE-2025-30358
- GitHub Advisory GHSA-f3mf-hm6v-jfhh
- NVD CVE-2025-30358
- OSV PYSEC-2026-1624
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.