CVE-2026-42344
CVE-2026-42344 is a medium-severity vulnerability with a CVSS 3.x base score of 6.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-367.
Key facts
- Severity: Medium (CVSS 3.x base score 6.3)
- EPSS exploit prediction: 0% (4th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-28854
- Weakness: CWE-367
- Published:
- Last modified:
Description
FastGPT is an AI Agent building platform. In versions 4.14.11 and prior, FastGPT's isInternalAddress() function in packages/service/common/system/utils.ts is vulnerable to DNS rebinding (TOCTOU — Time-of-Check to Time-of-Use). The function resolves the hostname via dns.resolve4()/dns.resolve6() and checks resolved IPs against private ranges, but the actual HTTP request happens in a separate call with a new DNS resolution, allowing the DNS record to change between validation and fetch. At time of publication, there are no publicly available patches.
Frequently asked questions
- What is CVE-2026-42344?
- FastGPT is an AI Agent building platform. In versions 4.14.11 and prior, FastGPT's isInternalAddress() function in packages/service/common/system/utils.ts is vulnerable to DNS rebinding (TOCTOU — Time-of-Check to Time-of-Use). The function resolves the hostname via dns.resolve4()/dns.resolve6() and checks resolved IPs against private ranges, but the actual HTTP request happens in a separate call with a new DNS resolution, allowing the DNS record to change between validation and fetch. At time of publication, there are no publicly available patches.
- How severe is CVE-2026-42344?
- CVE-2026-42344 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
- Is CVE-2026-42344 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-42344?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2026-42344 have an EU (EUVD) identifier?
- Yes. CVE-2026-42344 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-28854.
- When was CVE-2026-42344 published?
- CVE-2026-42344 was published on 2026-05-08 and last updated on 2026-06-17.
References
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