# Megaco flex scanner buffer overflow via oversized property parm name

CVE record · `CVE-2026-59250`

- **Identifiers:** `CVE-2026-59250`
- **State:** Confirmed
- **Severity:** CVSS 8.3 High
- **Critical:** No
- **CNA:** EEF
- **Weakness (CWE):** [CWE-120](https://cwe.mitre.org/data/definitions/120.html) · [CWE-787](https://cwe.mitre.org/data/definitions/787.html)
- **Tags:** [Memory corruption](https://agentprime.io/advisories/tag/memory-corruption.md)
- **Technologies:** [Erlang OTP](https://agentprime.io/advisories/technology/erlang-otp.md)
- **Published:** 27 Jul 2026
- **Updated:** 8 Sept 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: EEF) at 27 Jul 2026, 15:25 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Affected products, as the CNA wrote them

- Vendor: Erlang. Product: OTP.
  - unknown: `before 17.0` (otp)
  - affected: `17.0 to before 27.3.4.15` (otp)
  - affected: `28.0 to before 28.5.0.4` (otp)
  - affected: `29.0 to before 29.0.4` (otp)
  - Other versions: unaffected
  - Package name: `otp`
  - purl: `pkg:software-id/erlang.org/otp`
- Vendor: Erlang. Product: OTP.
  - unknown: `before 3.17.1` (otp)
  - affected: `3.17.1 to before 4.7.2.2` (otp)
  - affected: `4.8 to before 4.8.3.1` (otp)
  - affected: `4.9 to before 4.9.1` (otp)
  - Other versions: unaffected
  - Package name: `megaco`
  - purl: `pkg:otp/megaco?repository_url=https:%2F%2Fgithub.com%2Ferlang%2Fotp&vcs_url=git%2Bhttps:%2F%2Fgithub.com%2Ferlang%2Fotp.git`
- Vendor: Erlang. Product: OTP.
  - affected: `84adefa331c4159d432d22840663c38f155cd4c1 to before 8704c8f550a11ed5f825e3c011ecb03565b79c4f` (git)
  - Other versions: unaffected
  - Package name: `erlang/otp`
  - Collection: `https://github.com`
  - purl: `pkg:github/erlang/otp`

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

- 8.3 High, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N`, from CNA (EEF)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0078, the 56th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the CVE Program, published 27 Jul 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-59250](https://www.cve.org/CVERecord?id=CVE-2026-59250)
- [NVD: CVE-2026-59250](https://nvd.nist.gov/vuln/detail/CVE-2026-59250)

### References from the CNA

- <https://github.com/erlang/otp/security/advisories/GHSA-7xgh-gmgf-q2g7> (vendor-advisory, related)
- <https://cna.erlef.org/cves/CVE-2026-59250.html> (related)
- <https://osv.dev/vulnerability/EEF-CVE-2026-59250> (related)
- <https://www.erlang.org/doc/system/versions.html#order-of-versions> (version-scheme)
- <https://github.com/erlang/otp/commit/8704c8f550a11ed5f825e3c011ecb03565b79c4f> (patch)

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2026-59250>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-59250/>. Everything for agents: <https://agentprime.io/llms.txt>.