CVE-2026-45103

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 75% of all CVEs by exploit prediction. 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, secondary
Elevated
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

OpenSIPS is a Session Initiation Protocol (SIP) server implementation. In versions prior to 3.6.6 and 4.0.0-rc1, the TCP message framing layer parses the Content-Length header using unsigned int arithmetic with no overflow check. When an attacker sends a Content-Length value that overflows unsigned int (e.g., 4294967296), the framing layer computes a wrapped-around value (e.g., 0) and splits the TCP stream at the wrong boundary, causing the body of the first SIP message to be processed as a separate message and enabling SIP message smuggling. Because Content-Length is parsed in the transport layer before authentication, an unauthenticated, network-based attacker can smuggle arbitrary SIP messages over any TCP-based transport (proto_tcp, proto_tls, proto_ws, proto_wss) on any instance with TCP enabled, with no routing-script preconditions. This allows smuggled messages to bypass front-end SBC/proxy security policies, inherit the connection's authentication context, and evade rate limiting. This issue has been fixed in versions 3.6.6 and 4.0.0-rc1.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
65(Attend)
EG Risk 65/100SSVC: Attend

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
Severity75% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
25%
KEV
Not listed

Published

August 4, 2026

Last Modified

August 5, 2026

Advisory Details (3)

Auto-updated Aug 4, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit.
github_commit

commit 5f103eff (OpenSIPS/opensips)

Fix landed in OpenSIPS/opensips commit 5f103eff — awaiting tagged release

https://github.com/OpenSIPS/opensips/commit/5f103eff
github_commit

commit 4d23613b (OpenSIPS/opensips)

Fix landed in OpenSIPS/opensips commit 4d23613b — awaiting tagged release

https://github.com/OpenSIPS/opensips/commit/4d23613b
github Patch Available🟡 PoC Available

SIP Message Smuggling via TCP Content-Length Integer Overflow · Advisory · OpenSIPS/opensips · GitHub

https://github.com/OpenSIPS/opensips/security/advisories/GHSA-jv35-555v-54jh

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 49× 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. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-29 21:41 UTCEG score recompute
  3. 2026-08-28 21:41 UTCEPSS rescore
  4. 2026-08-27 19:57 UTCEG score recompute
  5. 2026-08-27 14:25 UTCEPSS rescore
  6. 2026-08-26 19:09 UTCEG score recompute
  7. 2026-08-26 14:46 UTCEPSS rescore
  8. 2026-08-25 19:52 UTCEG score recompute
  9. 2026-08-25 13:49 UTCEPSS rescore
  10. 2026-08-24 21:39 UTCEG score recompute
  11. 2026-08-24 10:08 UTCEG score recompute
  12. 2026-08-23 00:47 UTCEG score recompute
  13. 2026-08-23 00:19 UTCEPSS rescore
  14. 2026-08-22 02:35 UTCEG score recompute
  15. 2026-08-21 23:49 UTCEPSS rescore
  16. 2026-08-21 04:21 UTCEG score recompute
  17. 2026-08-20 22:55 UTCEPSS rescore
  18. 2026-08-19 18:55 UTCEG score recompute
  19. 2026-08-19 17:04 UTCEPSS rescore
  20. 2026-08-18 18:53 UTCEG score recompute
  21. 2026-08-18 13:48 UTCEPSS rescore
  22. 2026-08-17 20:39 UTCEG score recompute
  23. 2026-08-17 13:47 UTCEPSS rescore
  24. 2026-08-16 22:27 UTCEG score recompute
  25. 2026-08-16 14:56 UTCEPSS rescore
Show 24 more
  1. 2026-08-16 11:20 UTCEG score recompute
  2. 2026-08-16 02:14 UTCEPSS rescore
  3. 2026-08-15 02:00 UTCEG score recompute
  4. 2026-08-15 01:30 UTCEPSS rescore
  5. 2026-08-14 03:47 UTCEG score recompute
  6. 2026-08-13 22:00 UTCEPSS rescore
  7. 2026-08-12 18:17 UTCEG score recompute
  8. 2026-08-12 13:51 UTCEPSS rescore
  9. 2026-08-11 20:00 UTCEG score recompute
  10. 2026-08-11 08:51 UTCEG score recompute
  11. 2026-08-11 00:00 UTCEPSS rescore
  12. 2026-08-09 23:31 UTCEG score recompute
  13. 2026-08-09 13:46 UTCEPSS rescore
  14. 2026-08-09 01:18 UTCEG score recompute
  15. 2026-08-08 16:37 UTCEPSS rescore
  16. 2026-08-08 03:04 UTCEG score recompute
  17. 2026-08-06 17:45 UTCEG score recompute
  18. 2026-08-06 13:46 UTCEPSS rescore
  19. 2026-08-05 19:31 UTCEG score recompute
  20. 2026-08-05 19:17 UTCEPSS rescore
  21. 2026-08-05 18:26 UTCEG score recompute
  22. 2026-08-04 22:31 UTCEG score recompute
  23. 2026-08-04 22:06 UTCEG score recompute
  24. 2026-08-04 22:05 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-45103?
CVE-2026-45103 is a high vulnerability published on August 4, 2026. OpenSIPS is a Session Initiation Protocol (SIP) server implementation. In versions prior to 3.6.6 and 4.0.0-rc1, the TCP message framing layer parses the Content-Length header using unsigned int arithmetic with no overflow check. When an attacker sends a Content-Length value that overflows unsigned…
When was CVE-2026-45103 disclosed?
CVE-2026-45103 was first published in the National Vulnerability Database on August 4, 2026, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-45103 actively exploited?
CVE-2026-45103 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 74.7% of all scored CVEs.
What is the CVSS score of CVE-2026-45103?
CVE-2026-45103 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-45103?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-45103, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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