ReDoS (Regular Expression Denial of Service) in gaizhenbiao/chuanhuchatgpt

published 2025-03-20 19 mo ago modified 2026-06-17 4 mo ago also PYSEC-2025-94 , EUVD-2025-7047

cvss: 6.5; version 3.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.7%; EPSS 0.7% chance of exploitation in 30 days, percentile 55%
public exploits: 0; none known

A Regular Expression Denial of Service (ReDoS) vulnerability exists in gaizhenbiao/chuanhuchatgpt, as of commit 20b2e02. The server uses the regex pattern `r'<[^>]+>'` to parse user input. In Python's default regex engine, this pattern can take polynomial time to match certain crafted inputs. An attacker can exploit this by uploading a malicious JSON payload, causing the server to consume 100% CPU for an extended period. This can lead to a Denial of Service (DoS) condition, potentially affecting the entire server.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 19 mo ago (2025-03-20)

Exploit prediction

0.74% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

huntr.com https://huntr.com/bounties/8291f8d0-5060-47e7-9986-1f411310fb7b referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.0	6.5	CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
OSV	3.0	6.5	CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem	package	affected	fixed in
pypi	chuanhuchatgpt	<=2024-09-19	no fix listed

Affected products

gaizhenbiao gaizhenbiao/chuanhuchatgpt

Classification

Weakness

CWE-1333 Inefficient Regular Expression Complexity

References

huntr.com /bounties/8291f8d0-5060-47e7-9986-1f411310fb7b
exploit, third-party-advisory, evidence

Sources

Fencer Vulns 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.

Summary