CVE-2026-90473

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreHIGH confidence

Score 5.3 from GitHub Security Advisory published 2026-09-12. a secondary CVSS source baseline 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0

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

msgpack-java through 0.9.12 contains an integer overflow vulnerability in MessageUnpacker.skipValue() when processing MAP32 containers with large element counts. Attackers can supply a MAP32 element count at or above 0x40000000 that wraps when doubled, causing the parser cursor to desynchronize and attacker-controlled data to be returned in place of later fields.

CVSS v3
5.3
EG Score
5.3(high)
EG Risk
28(Track)
EG Risk 28/100SSVC: Track

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%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
15%
KEV
Not listed

Published

September 12, 2026

Last Modified

September 12, 2026

Advisory Details (4)

Auto-updated Sep 12, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic

msgpack-java through 0.9.12 Integer Overflow via MAP32 | Advisories | VulnCheck

https://www.vulncheck.com/advisories/msgpack-java-through-0.9.12-integer-overflow-via-map32
generic🟡 PoC Available

[Security Disclosure] MAP32 Integer Overflow in `skipValue()` — Cursor Desynchronization · Issue #1014 · msgpack/msgpack-java · GitHub

https://github.com/msgpack/msgpack-java/issues/1014
generic

msgpack-java/msgpack-core/src/main/java/org/msgpack/core/MessageUnpacker.java at v0.9.12 · msgpack/msgpack-java · GitHub

https://github.com/msgpack/msgpack-java/blob/v0.9.12/msgpack-core/src/main/java/org/msgpack/core/MessageUnpacker.java#L573-L581
generic

GitHub - msgpack/msgpack-java: MessagePack serializer implementation for Java / msgpack.org[Java] · GitHub

https://github.com/msgpack/msgpack-java

Vendor Advisories for CVE-2026-90473(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 20× in last 7d / 28× 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. 2026-09-21 07:40 UTCEG score recompute
  2. 2026-09-21 07:40 UTCGHSA enrichment
  3. 2026-09-20 20:16 UTCEPSS rescore
  4. 2026-09-20 08:05 UTCEG score recompute
  5. 2026-09-20 08:05 UTCGHSA enrichment
  6. 2026-09-19 08:30 UTCEG score recompute
  7. 2026-09-19 08:30 UTCGHSA enrichment
  8. 2026-09-18 19:28 UTCEPSS rescore
  9. 2026-09-18 08:56 UTCEG score recompute
  10. 2026-09-18 08:56 UTCGHSA enrichment
  11. 2026-09-17 19:32 UTCEPSS rescore
  12. 2026-09-17 09:21 UTCEG score recompute
  13. 2026-09-17 09:21 UTCGHSA enrichment
  14. 2026-09-16 14:09 UTCEPSS rescore
  15. 2026-09-16 09:46 UTCEG score recompute
  16. 2026-09-16 09:46 UTCGHSA enrichment
  17. 2026-09-16 05:15 UTCEPSS rescore
  18. 2026-09-15 10:11 UTCEG score recompute
  19. 2026-09-15 10:11 UTCGHSA enrichment
  20. 2026-09-15 03:12 UTCEPSS rescore
  21. 2026-09-14 10:35 UTCEG score recompute
  22. 2026-09-14 10:35 UTCGHSA enrichment
  23. 2026-09-13 16:48 UTCEPSS rescore
  24. 2026-09-13 10:59 UTCEG score recompute
  25. 2026-09-13 10:59 UTCGHSA enrichment
Show 3 more
  1. 2026-09-12 11:24 UTCEG score recompute
  2. 2026-09-12 11:14 UTCEG score recompute
  3. 2026-09-12 11:13 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-90473?
CVE-2026-90473 is a medium vulnerability published on September 12, 2026. msgpack-java through 0.9.12 contains an integer overflow vulnerability in MessageUnpacker.skipValue() when processing MAP32 containers with large element counts. Attackers can supply a MAP32 element count at or above 0x40000000 that wraps when doubled, causing the parser cursor to desynchronize and…
When was CVE-2026-90473 disclosed?
CVE-2026-90473 was first published in the National Vulnerability Database on September 12, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-90473 actively exploited?
CVE-2026-90473 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 84.6% of all scored CVEs.
What is the CVSS score of CVE-2026-90473?
CVE-2026-90473 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-90473?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-90473, 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.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-90473

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