CVE-2026-55894

MEDIUMPre-NVD 6.86.8—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 89% 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 — 3 sources updated this weekElevated
6.8EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.8Exploit: Elevated riskExposed: 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_disassemble() function computes an idx value from a raw 16-bit instruction without ensuring it is within the active mode-specific decode[] function-pointer table. An application using CS_ARCH_SH with CS_MODE_SH2A or CS_MODE_SH4A and CS_MODE_SHFPU can pass crafted bytecode through cs_disasm_iter() or cs_disasm(), causing the decode[idx] test to read outside the table and terminate the process with a segmentation fault. No code execution or information disclosure was demonstrated. This issue is fixed in version 6.0.0-Alpha10.

CVSS v3
6.8
EG Score
6.8(medium)
EG Risk
47(Track)
EG Risk 47/100SSVC: 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
Severity68% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
11%
KEV
Not listed

Published

August 20, 2026

Last Modified

September 18, 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 `sh_disassemble` out-of-bounds read via crafted SH2A bytecode · Advisory · capstone-engine/capstone · GitHub

https://github.com/capstone-engine/capstone/security/advisories/GHSA-gf2c-xwcp-hvf4

Vendor Advisories for CVE-2026-55894(1)

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

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.

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
capstone4.0.2-5 ... 5.0.9-1 (11 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
capstone5.0.6-1, 5.0.7-1, 5.0.7-1~deb13u1, 5.0.7-2, 5.0.9-1——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
capstone5.0.6-1, 5.0.7-1, 5.0.7-1~deb13u1, 5.0.7-2, 5.0.9-1——

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 16× in last 7d / 71× 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. 2026-09-20 20:51 UTCEG score recompute
  2. 2026-09-20 20:51 UTCVendor advisory
  3. 2026-09-20 20:16 UTCEPSS rescore
  4. 2026-09-19 20:35 UTCEG score recompute
  5. 2026-09-19 20:35 UTCVendor advisory
  6. 2026-09-18 20:19 UTCEG score recompute
  7. 2026-09-18 20:19 UTCVendor advisory
  8. 2026-09-18 19:28 UTCEPSS rescore
  9. 2026-09-18 04:16 UTCVendor advisory
  10. 2026-09-17 04:00 UTCEG score recompute
  11. 2026-09-17 04:00 UTCVendor advisory
  12. 2026-09-16 14:08 UTCEPSS rescore
  13. 2026-09-16 03:44 UTCVendor advisory
  14. 2026-09-15 03:28 UTCEG score recompute
  15. 2026-09-15 03:28 UTCVendor advisory
  16. 2026-09-15 03:11 UTCEPSS rescore
  17. 2026-09-14 03:12 UTCEG score recompute
  18. 2026-09-14 03:12 UTCVendor advisory
  19. 2026-09-13 16:47 UTCEPSS rescore
  20. 2026-09-13 02:57 UTCEG score recompute
  21. 2026-09-13 02:57 UTCVendor advisory
  22. 2026-09-12 02:41 UTCEG score recompute
  23. 2026-09-12 02:41 UTCVendor advisory
  24. 2026-09-11 14:53 UTCEPSS rescore
  25. 2026-09-11 02:24 UTCEG score recompute
Show 52 more
  1. 2026-09-11 02:24 UTCVendor advisory
  2. 2026-09-10 09:35 UTCEPSS rescore
  3. 2026-09-10 02:08 UTCVendor advisory
  4. 2026-09-09 01:53 UTCEG score recompute
  5. 2026-09-09 01:53 UTCVendor advisory
  6. 2026-09-08 22:01 UTCEPSS rescore
  7. 2026-09-08 00:46 UTCEG score recompute
  8. 2026-09-08 00:46 UTCVendor advisory
  9. 2026-09-07 16:01 UTCEPSS rescore
  10. 2026-09-07 00:29 UTCEG score recompute
  11. 2026-09-07 00:29 UTCVendor advisory
  12. 2026-09-06 13:47 UTCEPSS rescore
  13. 2026-09-06 00:08 UTCEG score recompute
  14. 2026-09-06 00:08 UTCVendor advisory
  15. 2026-09-04 23:51 UTCEG score recompute
  16. 2026-09-04 23:51 UTCVendor advisory
  17. 2026-09-04 05:07 UTCEPSS rescore
  18. 2026-09-03 22:17 UTCVendor advisory
  19. 2026-09-02 21:08 UTCEG score recompute
  20. 2026-09-02 21:08 UTCVendor advisory
  21. 2026-09-02 14:12 UTCEPSS rescore
  22. 2026-09-01 20:31 UTCEG score recompute
  23. 2026-09-01 20:31 UTCVendor advisory
  24. 2026-09-01 13:54 UTCEPSS rescore
  25. 2026-09-01 04:40 UTCEPSS rescore
  26. 2026-08-31 20:15 UTCVendor advisory
  27. 2026-08-30 19:59 UTCEG score recompute
  28. 2026-08-30 19:59 UTCVendor advisory
  29. 2026-08-30 19:17 UTCEPSS rescore
  30. 2026-08-30 01:22 UTCEPSS rescore
  31. 2026-08-29 19:43 UTCEG score recompute
  32. 2026-08-29 19:43 UTCVendor advisory
  33. 2026-08-28 21:41 UTCEPSS rescore
  34. 2026-08-28 19:27 UTCVendor advisory
  35. 2026-08-27 18:21 UTCEG score recompute
  36. 2026-08-27 18:21 UTCVendor advisory
  37. 2026-08-27 14:25 UTCEPSS rescore
  38. 2026-08-26 17:53 UTCEG score recompute
  39. 2026-08-26 17:53 UTCVendor advisory
  40. 2026-08-26 14:46 UTCEPSS rescore
  41. 2026-08-25 17:12 UTCEG score recompute
  42. 2026-08-25 13:49 UTCEPSS rescore
  43. 2026-08-24 16:56 UTCEG score recompute
  44. 2026-08-23 15:59 UTCEG score recompute
  45. 2026-08-23 00:19 UTCEPSS rescore
  46. 2026-08-22 15:44 UTCEG score recompute
  47. 2026-08-21 23:49 UTCEPSS rescore
  48. 2026-08-21 15:21 UTCEG score recompute
  49. 2026-08-21 15:10 UTCEG score recompute
  50. 2026-08-20 22:24 UTCEG score recompute
  51. 2026-08-20 21:42 UTCEG score recompute
  52. 2026-08-20 21:41 UTCMITRE cvelistV5first tracked

Related CVEs(same vendor + same CWE)

Same vendor

1 shown

redhat:RHSA-2026:59419

Frequently asked(5)

What is CVE-2026-55894?
CVE-2026-55894 is a medium vulnerability published on August 20, 2026. Capstone is a disassembly framework. In 6.0.0-Alpha9 and earlier, Capstone's arch/SH/SHDisassembler.c shdisassemble() function computes an idx value from a raw 16-bit instruction without ensuring it is within the active mode-specific decode[] function-pointer table. An application using CSARCHSH…
When was CVE-2026-55894 disclosed?
CVE-2026-55894 was first published in the National Vulnerability Database on August 20, 2026, with the most recent update on September 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55894 actively exploited?
CVE-2026-55894 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 88.6% of all scored CVEs.
What is the CVSS score of CVE-2026-55894?
CVE-2026-55894 has a CVSS v3 base score of 6.8 (NVD).
How do I remediate CVE-2026-55894?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55894, 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

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