What is CVE-2026-78145?
A vulnerability has been found in CTFd up to 3.8.4. The affected element is the function _is_safe_url of the file CTFd/utils/validators/__init__.py. Such manipulation of the argument Next leads to open redirect. The attack can be launched remotely. The exploit has been disclosed to the public and may be used. The name of the patch is 5d8515842fd1ab2c3a9f2dde9ffca907aa334ea9. Upgrading the affected component is recommended.
The record classifies CVE-2026-78145 under weakness class CWE-601. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs a user to take an action first. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 43 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 4.3 — MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C - CVSS v4.0 base score
- 5.3
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P - EPSS (FIRST)
- 0.4% probability of exploitation in the next 30 days, higher than 34.7% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 3.5/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-08-23
Is CVE-2026-78145 being exploited?
It currently carries a trending score of 38 in the Threadlinqs vulnerability feed.
Affected products and versions
- (vendor unspecified): CTFd
How to fix CVE-2026-78145
No vendor patch reference has been recorded for CVE-2026-78145 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-78145
No threat campaign in the Threadlinqs corpus currently references CVE-2026-78145, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.
Sources
Enriched from CVE.org, GitHub Security Advisories, FIRST EPSS. Last verified by Threadlinqs on .