CVE-2026-5245
CVE-2026-5245 is a medium-severity vulnerability in Cesanta Mongoose with a CVSS 3.x base score of 5.6. 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-119.
Key facts
- Severity: Medium (CVSS 3.x base score 5.6)
- CVSS v2: 5.1
- CVSS v4: 2.9
- EPSS exploit prediction: 1% (49th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-18183
- Weakness: CWE-119
- Affected product: Cesanta Mongoose
- Published:
- Last modified:
Description
A vulnerability was found in Cesanta Mongoose up to 7.20. This impacts the function handle_mdns_record of the file mongoose.c of the component mDNS Record Handler. Performing a manipulation of the argument buf results in stack-based buffer overflow. Remote exploitation of the attack is possible. A high degree of complexity is needed for the attack. The exploitability is said to be difficult. The exploit has been made public and could be used. Upgrading to version 7.21 will fix this issue. The patch is named 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1. You should upgrade the affected component. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
Frequently asked questions
- What is CVE-2026-5245?
- A vulnerability was found in Cesanta Mongoose up to 7.20. This impacts the function handle_mdns_record of the file mongoose.c of the component mDNS Record Handler. Performing a manipulation of the argument buf results in stack-based buffer overflow. Remote exploitation of the attack is possible. A high degree of complexity is needed for the attack. The exploitability is said to be difficult. The exploit has been made public and could be used. Upgrading to version 7.21 will fix this issue. The patch is named 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1. You should upgrade the affected component. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
- How severe is CVE-2026-5245?
- CVE-2026-5245 has a CVSS 3.x base score of 5.6, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
- Is CVE-2026-5245 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-5245?
- CVE-2026-5245 affects Cesanta Mongoose. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2026-5245?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2026-5245 have an EU (EUVD) identifier?
- Yes. CVE-2026-5245 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18183.
- When was CVE-2026-5245 published?
- CVE-2026-5245 was published on 2026-04-02 and last updated on 2026-06-17.
References
- https://github.com/cesanta/mongoose/
- https://github.com/cesanta/mongoose/commit/0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1
- https://github.com/cesanta/mongoose/releases/tag/7.21
- https://vuldb.com/submit/770103
- https://vuldb.com/vuln/354826
- https://vuldb.com/vuln/354826/cti
Affected products (1)
- cpe:2.3:a:cesanta:mongoose:*:*:*:*:*:*:*:*
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- CVE-2018-20355 — Critical (CVSS 9.8): An invalid write of 8 bytes due to a use-after-free vulnerability in the mg_http_free_proto_data_cgi function call in…
All CVEs affecting Cesanta Mongoose →
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