# CVE-2026-57199: Asterisk: Asterisk app_sms.c copies externally controlled SMS lengths into fixed in-struct buffers

Status: published. Published: 2026-10-27. Updated: 2026-11-03.

Asterisk is an open source private branch exchange and telephony toolkit. Prior to Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3, `app_sms.c` copies externally controlled `SMS` lengths into `fixed in-struct buffers` without sufficient bounds checks, allowing an attacker to corrupt memory or crash Asterisk. The administrator must explicitly use the `SMS` dialplan application, which is useful when routing calls to or from `analog devices`, and must not have ensured that data passed to the application is valid. This issue is fixed in Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- asterisk / asterisk: < 20.20.1 (affected); >= 21.0.0-pre1, < 21.12.3 (affected); >= 22.0.0-pre1, < 22.10.1 (affected); >= 23.0.0-pre1, < 23.4.1 (affected). Source: CNA: GitHub_M
- asterisk / certified-asterisk: < 20.7-cert11 (affected); >= 22.8-cert1-pre1, < 22.8-cert3 (affected). Source: CNA: GitHub_M

## Severity and prioritization

- CVSS 4.0: 2.3 (low); CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N; source: CNA: GitHub_M

- CISA KEV: No listing in collected sources

- EPSS: 0.48% as of 2026-11-03; percentile 41.57%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-787

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/asterisk/asterisk/security/advisories/GHSA-q9fr-m7g8-6ph5 (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/asterisk/asterisk/commit/15c66022dc441ec63d7bd5f53cf7f35db72964be (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/asterisk/asterisk/commit/38a2059eb77a91a6b6e76eeba5875c2b96027368 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/asterisk/asterisk/commit/59b74276f24ba104d859f3f05897c9b8d835a28a (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/asterisk/asterisk/commit/60f4ef3deac6b9af30519b46c13f103264038b82 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/asterisk/asterisk/commit/661d6a2fc5cc7744ab9d849ed3c73ae5066386df (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/asterisk/asterisk/commit/7048a3841df99e090b9d87246600373581629c98 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/asterisk/asterisk/commit/f46f63bd4d33665d336cf8b5998650b915222549 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/asterisk/asterisk/releases/tag/20.20.1 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/asterisk/asterisk/releases/tag/21.12.3 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/asterisk/asterisk/releases/tag/22.10.1 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/asterisk/asterisk/releases/tag/23.4.1 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/asterisk/asterisk/releases/tag/certified-20.7-cert11 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/asterisk/asterisk/releases/tag/certified-22.8-cert3 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/asterisk/asterisk/tree/24.0.0-pre1 (CNA: GitHub_M; x_refsource_MISC)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-57199; retrieved 2026-11-03; source updated 2026-11-03

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-57199; retrieved 2026-11-03; source updated Not reported

Revision: 07e7594f685bff559e48ee7d123995f080da4638928a5cc63e592fbcfd5963c9

Canonical: https://y2.dev/cve/CVE-2026-57199

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.