CVE Explorer
CVE-2026-21868
Flag Forge is a Capture The Flag (CTF) platform. Versions 2.3.2 and below have a Regular Expression Denial of Service (ReDoS) vulnerability in the user profile API endpoint (/api/user/[username]). The application constructs a regular expression dynamically using unescaped user input (the username parameter). An attacker can exploit this by sending a specially crafted username containing regex meta-characters (e.g., deeply nested groups or quantifiers), causing the MongoDB regex engine to consume
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
0
Affected products and versions
1 source assertion{"product":"flagForge","vendor":"FlagForgeCTF","versions":[{"status":"affected","version":"< 2.3.3"}]}
- cve_program_cvelist_v5affectedurn:baitaphish:normalized-source-record:v2:6b4b54c88a965ebe8e3eeeb41062452338343ef6b4f0f07010391ebf8bb3a7ea · sha256:015ccf11e6740feb… · /containers/cna/affected/0
Provider-owned CVSS observations
1 source assertion{"metric":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"metric_type":"cvssV3_1"}
- cve_program_cvelist_v5cvssurn:baitaphish:normalized-source-record:v2:6b4b54c88a965ebe8e3eeeb41062452338343ef6b4f0f07010391ebf8bb3a7ea · sha256:015ccf11e6740feb… · /containers/cna/metrics/0/cvssV3_1
CWE assertions
1 source assertion{"cweId":"CWE-1333","description":"CWE-1333: Inefficient Regular Expression Complexity","lang":"en","type":"CWE"}
- cve_program_cvelist_v5cweurn:baitaphish:normalized-source-record:v2:6b4b54c88a965ebe8e3eeeb41062452338343ef6b4f0f07010391ebf8bb3a7ea · sha256:015ccf11e6740feb… · /containers/cna/problemTypes/0/descriptions/0
Source references
1 source assertion{"name":"https://github.com/FlagForgeCTF/flagForge/security/advisories/GHSA-949h-9824-xmcx","tags":["x_refsource_CONFIRM"],"url":"https://github.com/FlagForgeCTF/flagForge/security/advisories/GHSA-949h-9824-xmcx"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:6b4b54c88a965ebe8e3eeeb41062452338343ef6b4f0f07010391ebf8bb3a7ea · sha256:015ccf11e6740feb… · /containers/cna/references/0
Attribution and limitations
- CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →
Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.