CVE-2026-57166

MEDIUMNVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under NVD CVSS v3. EPSS exploit probability: 0.5% (43rd percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 5.3Exploit: None knownExposed services: Not assessed

A fix is referenced (a reference tagged "Patch", often a source commit), but no release containing it is confirmed — find the release that contains it; until it is applied, mitigate (WAF / firewall / segmentation).

PJSIP is a free and open source multimedia communication library written in C. Prior to commit 4472a31, a stack buffer overflow exists in the PJLIB-UTIL telnet CLI front-end when rendering feedback for an entered command line. Several command-line handling paths write an attacker-influenced amount of data into fixed-size buffers without sufficient bounds checking, so a long command line can overflow them. This affects only applications that enable the telnet CLI front-end (e.g. pj_cli_telnet_create() / --cli-telnet-port). The telnet CLI is an interactive administration interface with no authentication, so any client able to reach it can already issue arbitrary CLI commands. A malformed or overly long command line can overflow a fixed-size stack buffer while rendering command-line feedback, which may lead to application termination. Because reaching this code already requires access to the unauthenticated CLI, the impact beyond that existing access is limited. Applications that do not enable the telnet CLI front-end are not affected. This issue has been patched via commit 4472a31.

CVSS v3
5.3
EG Score
5.3MEDIUMmedium confidence
EG Risk
39
EG Risk 39/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity53% × 45%
Exploitation1% × 40%
Automatability100% × 15%
CISA SSVC: Track at low or medium mission impact; Attend at high (mission-essential systems).
Action: A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it and apply that within your standard update timelines at low or medium mission impact and sooner than that at high; until then, restrict network exposure of the affected system or apply the vendor's mitigation.
EPSS PROB
0.5%
EPSS %ILE
43rd
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Attend at high (mission-essential systems).

A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it and apply that within your standard update timelines at low or medium mission impact and sooner than that at high; until then, restrict network exposure of the affected system or apply the vendor's mitigation.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 4, 2026

Last Modified

September 11, 2026

Advisory Details (2)

Auto-updated Sep 4, 2026
Fix referenced — no release confirmed yet. Sources: github_commit, github.
github_commit

commit 4472a31d77a7 (pjsip/pjproject)

Fix landed in pjsip/pjproject commit 4472a31d77a7 — awaiting tagged release

https://github.com/pjsip/pjproject/commit/4472a31d77a7506ff175dad5abef490f4e31bed1
githubMentions a patch (unverified)

Pre-authentication overflow in the telnet CLI command line · Advisory · pjsip/pjproject · GitHub

https://github.com/pjsip/pjproject/security/advisories/GHSA-9c8q-h38q-p85j

Affected Packages

(1 across 1 ecosystem)
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
asterisk0.1.11-3 ... 1:22.9.0+dfsg+~cs6.16.60671434-1 (296 versions)
  • every version on: no fix on record
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 11× in last 7d / 53× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-09 23:32 UTCEG score recompute
  2. 2026-10-09 20:07 UTCEPSS rescore
  3. 2026-10-09 01:09 UTCEG score recompute
  4. 2026-10-08 17:13 UTCEPSS rescore
  5. 2026-10-07 23:48 UTCEPSS rescore
  6. 2026-10-06 16:38 UTCEG score recompute
  7. 2026-10-06 15:18 UTCEPSS rescore
  8. 2026-10-05 18:07 UTCEG score recompute
  9. 2026-10-05 17:43 UTCEPSS rescore
  10. 2026-10-04 23:22 UTCEPSS rescore
  11. 2026-10-03 21:20 UTCEG score recompute
  12. 2026-10-03 14:26 UTCEPSS rescore
  13. 2026-10-02 22:56 UTCEG score recompute
  14. 2026-10-02 17:56 UTCEPSS rescore
  15. 2026-10-02 00:30 UTCEG score recompute
  16. 2026-10-01 19:50 UTCEPSS rescore
  17. 2026-10-01 01:05 UTCEG score recompute
  18. 2026-09-30 15:03 UTCEPSS rescore
  19. 2026-09-30 02:40 UTCEG score recompute
  20. 2026-09-29 15:22 UTCEPSS rescore
  21. 2026-09-28 21:20 UTCEG score recompute
  22. 2026-09-28 13:51 UTCEPSS rescore
  23. 2026-09-27 22:56 UTCEG score recompute
  24. 2026-09-27 13:48 UTCEPSS rescore
  25. 2026-09-27 00:32 UTCEG score recompute
Show 41 more
  1. 2026-09-26 15:59 UTCEPSS rescore
  2. 2026-09-26 02:09 UTCEG score recompute
  3. 2026-09-24 19:04 UTCEG score recompute
  4. 2026-09-24 14:04 UTCEPSS rescore
  5. 2026-09-23 20:40 UTCEG score recompute
  6. 2026-09-23 17:54 UTCEPSS rescore
  7. 2026-09-22 22:17 UTCEG score recompute
  8. 2026-09-21 23:52 UTCEG score recompute
  9. 2026-09-21 01:29 UTCEG score recompute
  10. 2026-09-20 20:16 UTCEPSS rescore
  11. 2026-09-20 02:59 UTCEG score recompute
  12. 2026-09-19 04:35 UTCEG score recompute
  13. 2026-09-18 19:28 UTCEPSS rescore
  14. 2026-09-18 06:11 UTCEG score recompute
  15. 2026-09-17 19:31 UTCEPSS rescore
  16. 2026-09-17 07:47 UTCEG score recompute
  17. 2026-09-16 14:08 UTCEPSS rescore
  18. 2026-09-16 09:23 UTCEG score recompute
  19. 2026-09-16 05:15 UTCEPSS rescore
  20. 2026-09-15 10:59 UTCEG score recompute
  21. 2026-09-15 03:11 UTCEPSS rescore
  22. 2026-09-14 12:22 UTCEG score recompute
  23. 2026-09-13 16:47 UTCEPSS rescore
  24. 2026-09-12 15:35 UTCEG score recompute
  25. 2026-09-11 17:12 UTCEG score recompute▼ 1.00
  26. 2026-09-11 17:11 UTCNVD updateCVSS v3 → 5.3
  27. 2026-09-11 14:53 UTCEPSS rescore
  28. 2026-09-11 14:39 UTCEG score recompute
  29. 2026-09-10 16:15 UTCEG score recompute
  30. 2026-09-10 09:35 UTCEPSS rescore
  31. 2026-09-09 17:34 UTCEG score recompute
  32. 2026-09-09 16:53 UTCEG score recompute
  33. 2026-09-08 22:01 UTCEPSS rescore
  34. 2026-09-08 12:54 UTCEG score recompute
  35. 2026-09-07 16:01 UTCEPSS rescore
  36. 2026-09-06 15:23 UTCEG score recompute
  37. 2026-09-06 13:47 UTCEPSS rescore
  38. 2026-09-05 16:59 UTCEG score recompute
  39. 2026-09-04 18:34 UTCEG score recompute
  40. 2026-09-04 17:20 UTCEG score recompute
  41. 2026-09-04 17:19 UTCMITRE cvelistV5first tracked

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-57166?
CVE-2026-57166 is a medium vulnerability published on September 4, 2026. PJSIP is a free and open source multimedia communication library written in C. Prior to commit 4472a31, a stack buffer overflow exists in the PJLIB-UTIL telnet CLI front-end when rendering feedback for an entered command line. Several command-line handling paths write an attacker-influenced amount…
When was CVE-2026-57166 disclosed?
CVE-2026-57166 was first published on September 4, 2026, with the most recent update on September 11, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-57166 actively exploited?
CVE-2026-57166 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (43rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-57166?
CVE-2026-57166 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-57166?
A fix for CVE-2026-57166 is referenced (a reference tagged "Patch", often a source commit), but EchelonGraph has no release containing it on record. Check that reference and the vendor's advisory for a release that contains the fix and update to it; until then, restrict network exposure of the affected system or apply the vendor's mitigation.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-57166

Explore →

Is Your Infrastructure Affected by CVE-2026-57166?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs