MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, MessagePack-CSharp's JSON conversion helpers contain multiple recursion paths that do not consistently enforce a depth limit. These paths are in the JSON conversion component rather than normal typed MessagePack deserialization. MessagePackSerializer.ConvertFromJson recursively processes nested JSON arrays and objects in FromJsonCore() without consulting MessagePackSecurity.MaximumObjectGraphDepth. TinyJsonReader.ReadNextToken() recursively consumes comma and colon separator characters, allowing even malformed JSON with long separator runs to consume one stack frame per character. MessagePackSerializer.ConvertToJson applies depth checks to arrays and maps, but the typeless extension branch for ext-100 recursively calls ToJsonCore() without applying MessagePackSecurity.DepthStep(ref reader). Each path can allow attacker-controlled input to exhaust the process stack and trigger an uncatchable StackOverflowException instead of failing with a catchable parse or serialization exception. This vulnerability is fixed in 2.5.301 and 3.1.7.
CVE-2026-48512
This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 86% 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).
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EPSS
- 13.9%
- KEV
- Not listed
Published
June 22, 2026
Last Modified
June 25, 2026
Advisory Details (1)
Auto-updated Jun 23, 2026JSON conversion APIs can recurse without consistent depth enforcement · Advisory · MessagePack-CSharp/MessagePack-CSharp · GitHub
https://github.com/MessagePack-CSharp/MessagePack-CSharp/security/advisories/GHSA-cj9g-3mj2-g8vvVendor Advisories for CVE-2026-48512(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 19× in last 7d / 47× 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.
- 2026-07-07 00:06 UTCEG score recompute
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 11:38 UTCEG score recompute
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-05 23:10 UTCEG score recompute
- 2026-07-05 10:37 UTCEG score recompute
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-04 22:06 UTCEG score recompute
- 2026-07-04 09:38 UTCEG score recompute
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-03 21:11 UTCEG score recompute
- 2026-07-03 08:44 UTCEG score recompute
- 2026-07-02 20:16 UTCEG score recompute
- 2026-07-02 07:49 UTCEG score recompute
- 2026-07-01 19:22 UTCEG score recompute
- 2026-07-01 15:07 UTCEPSS rescore
- 2026-07-01 06:54 UTCEG score recompute
- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-30 18:26 UTCEG score recompute
- 2026-06-30 05:59 UTCEG score recompute
- 2026-06-29 17:32 UTCEG score recompute
- 2026-06-29 14:06 UTCEPSS rescore
- 2026-06-29 14:06 UTCEPSS rescore
- 2026-06-29 05:05 UTCEG score recompute
- 2026-06-28 16:37 UTCEG score recompute
Show 22 moreShow fewer
- 2026-06-28 14:07 UTCEPSS rescore
- 2026-06-28 04:56 UTCEPSS rescore
- 2026-06-28 04:56 UTCEPSS rescore
- 2026-06-28 04:10 UTCEG score recompute
- 2026-06-27 15:42 UTCEG score recompute
- 2026-06-27 03:15 UTCEG score recompute
- 2026-06-27 03:08 UTCEPSS rescore
- 2026-06-26 14:47 UTCEG score recompute
- 2026-06-26 02:19 UTCEG score recompute
- 2026-06-25 17:48 UTCNVD updateCVSS v3 → 7.5 · severity → HIGH
- 2026-06-25 15:46 UTCMITRE cvelistV5CVSS v3 → 6.3 · severity → MEDIUM
- 2026-06-25 13:52 UTCEG score recompute
- 2026-06-25 13:49 UTCEPSS rescore
- 2026-06-25 01:24 UTCEG score recompute
- 2026-06-24 14:05 UTCEPSS rescore
- 2026-06-24 12:57 UTCEG score recompute
- 2026-06-24 00:28 UTCEG score recompute▲ 1.20
- 2026-06-23 21:33 UTCEPSS rescore
- 2026-06-23 21:33 UTCEPSS rescore
- 2026-06-23 17:33 UTCNVD updateCVSS v3 → 7.5 · severity → HIGH
- 2026-06-23 00:01 UTCEG score recompute
- 2026-06-23 00:00 UTCMITRE cvelistV5first tracked
Frequently asked(5)
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Dependency Blast Radius
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