CVE-2026-55893

HIGHPre-NVD 7.37.3—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.1%, top 96% 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
Trending — Patch released this week
7.3EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.3Exploit: None knownExposed: 0

A fix is available — apply it.

Capstone is a disassembly framework. In 6.0.0-Alpha9 and earlier, Capstone's arch/SH/SHDisassembler.c SH floating-point decoders such as opFADD, opFMUL, and opFSUB call set_reg() and set_reg_n() using sh_info.op.op_count without checking the fixed-size operands[] array. Repeated crafted instructions processed through cs_disasm_iter() or cs_disasm() with CS_ARCH_SH, CS_MODE_SH2A or CS_MODE_SH4A, CS_MODE_SHFPU, and CS_OPT_DETAIL can increment the operand count beyond the 176-byte sh_info allocation and perform a four-byte heap buffer overflow write. The corruption can crash the process and may enable code execution depending on heap layout. This issue is fixed in version 6.0.0-Alpha10.

CVSS v3
7.3
EG Score
7.3(medium)
EG Risk
33(Track)
EG Risk 33/100SSVC: 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
Severity73% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
4%
KEV
Not listed

Published

August 20, 2026

Last Modified

August 21, 2026

Advisory Details (6)

Auto-updated Aug 20, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_pr, github_commit, github_release.
github_release Patch Available

6.0.0-Alpha10

Patch available: capstone-engine/capstone 6.0.0-Alpha10

https://github.com/capstone-engine/capstone/releases/tag/6.0.0-Alpha10
github_commit

commit e17ee44a8307 (capstone-engine/capstone)

Fix landed in capstone-engine/capstone commit e17ee44a8307 — awaiting tagged release

https://github.com/capstone-engine/capstone/commit/e17ee44a8307ea33375b4727ac4f987650bf7bed
github_commit

commit 09e76802380b (capstone-engine/capstone)

Fix landed in capstone-engine/capstone commit 09e76802380b — awaiting tagged release

https://github.com/capstone-engine/capstone/commit/09e76802380b9e94d9720c44458d9d5282219e7e
github_pr

V5: Fix OOB reads/writes - CVE-2026-55893 & CVE-2026-55894

Fix merged in capstone-engine/capstone PR #2969 on 2026-06-18 — awaiting tagged release

https://github.com/capstone-engine/capstone/pull/2969
github_pr

Fix OOB reads/writes - CVE-2026-55893 & CVE-2026-55894

Fix merged in capstone-engine/capstone PR #2968 on 2026-06-18 — awaiting tagged release

https://github.com/capstone-engine/capstone/pull/2968
github Patch Available🟡 PoC Available

Capstone SH disassembler `set_reg_n` heap buffer overflow via crafted SH2A FPU bytecode · Advisory · capstone-engine/capstone · GitHub

https://github.com/capstone-engine/capstone/security/advisories/GHSA-3hpv-wr3j-rxwh

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatcapstone-main-5.0.8-0.3.hum12026-08-25redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

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

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 19× 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. 2026-08-30 04:53 UTCEG score recompute
  2. 2026-08-30 04:53 UTCVendor advisory
  3. 2026-08-30 01:22 UTCEPSS rescore
  4. 2026-08-29 15:42 UTCVendor advisory
  5. 2026-08-29 02:31 UTCEG score recompute
  6. 2026-08-29 02:31 UTCVendor advisory
  7. 2026-08-28 21:41 UTCEPSS rescore
  8. 2026-08-28 13:19 UTCVendor advisory
  9. 2026-08-28 00:03 UTCEG score recompute
  10. 2026-08-28 00:03 UTCVendor advisory
  11. 2026-08-27 14:25 UTCEPSS rescore
  12. 2026-08-27 10:51 UTCVendor advisory
  13. 2026-08-26 21:39 UTCEG score recompute
  14. 2026-08-26 21:39 UTCVendor advisory
  15. 2026-08-26 14:46 UTCEPSS rescore
  16. 2026-08-26 08:28 UTCVendor advisory
  17. 2026-08-25 19:17 UTCEG score recompute
  18. 2026-08-25 13:49 UTCEPSS rescore
  19. 2026-08-24 16:56 UTCEG score recompute
  20. 2026-08-23 00:46 UTCEG score recompute
  21. 2026-08-23 00:19 UTCEPSS rescore
  22. 2026-08-22 11:36 UTCEG score recompute
  23. 2026-08-21 23:49 UTCEPSS rescore
  24. 2026-08-21 22:25 UTCEG score recompute
  25. 2026-08-21 21:52 UTCEG score recompute
Show 3 more
  1. 2026-08-20 22:24 UTCEG score recompute
  2. 2026-08-20 21:42 UTCEG score recompute
  3. 2026-08-20 21:41 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-55893?
CVE-2026-55893 is a high vulnerability published on August 20, 2026. Capstone is a disassembly framework. In 6.0.0-Alpha9 and earlier, Capstone's arch/SH/SHDisassembler.c SH floating-point decoders such as opFADD, opFMUL, and opFSUB call setreg() and setregn() using shinfo.op.opcount without checking the fixed-size operands[] array. Repeated crafted instructions…
When was CVE-2026-55893 disclosed?
CVE-2026-55893 was first published in the National Vulnerability Database on August 20, 2026, with the most recent update on August 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55893 actively exploited?
CVE-2026-55893 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 96.3% of all scored CVEs.
What is the CVSS score of CVE-2026-55893?
CVE-2026-55893 has a CVSS v3 base score of 7.3 (NVD).
How do I remediate CVE-2026-55893?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55893, 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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