CVE-2026-55893

HIGHPre-NVD 7.37.3
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This high-severity CVE scores 7.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2% (7th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Trending — 3 sources updated this week
7.3EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 7.3Exploit: None knownExposed services: Not assessed

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
7.3HIGHmedium confidence
EG Risk
33
EG Risk 33/100

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 (value × EchelonGraph’s weight)
Severity73% × 45%
The EG Score, 7.3 of 10.
Exploitation0.2% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
7th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

August 20, 2026

Last Modified

September 18, 2026

Advisory Details (6)

Auto-updated Aug 20, 2026
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 pull request

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 pull request

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 advisoryMentions a patch (unverified)

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

Vendor Advisories for CVE-2026-55893(2)

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 / EcosystemFix (by version range) / 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 rangeFix by version rangeDependents
capstone4.0.2-5 ... 5.0.9-1 (11 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
capstone5.0.6-1, 5.0.7-1, 5.0.7-1~deb13u1, 5.0.7-2, 5.0.9-1
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
capstone5.0.6-1, 5.0.7-1, 5.0.7-1~deb13u1, 5.0.7-2, 5.0.9-1
  • every version on: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 15× in last 7d / 95× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 97 of 171 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 3 repeat rows among the latest 100 are merged into the row they repeat. The 74 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  2. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  3. 2026-10-12 15:55 UTCEG score recompute
  4. 2026-10-11 19:38 UTCEG score recompute
  5. 2026-10-11 16:53 UTCEG score recompute
  6. 2026-10-11 14:16 UTCEG score recompute
  7. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  9. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  10. 2026-10-09 08:15 UTCEG score recompute
  11. 2026-10-09 08:15 UTCVendor advisory
  12. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  13. 2026-10-08 05:12 UTCEG score recompute
  14. 2026-10-08 05:12 UTCVendor advisory
  15. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  16. 2026-10-07 06:02 UTCVendor advisory
  17. 2026-10-06 16:52 UTCEG score recompute
  18. 2026-10-06 16:52 UTCVendor advisory
  19. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  20. 2026-10-06 03:12 UTCVendor advisory
  21. 2026-10-06 03:12 UTCEG score recompute
  22. 2026-10-06 03:12 UTCVendor advisory
  23. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  24. 2026-10-05 10:03 UTCEG score recompute
  25. 2026-10-05 10:03 UTCVendor advisory
Show 72 more
  1. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  2. 2026-10-04 20:51 UTCVendor advisory
  3. 2026-10-04 06:31 UTCVendor advisory
  4. 2026-10-03 17:20 UTCEG score recompute
  5. 2026-10-03 17:20 UTCVendor advisory
  6. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  7. 2026-10-03 04:09 UTCEG score recompute
  8. 2026-10-03 04:09 UTCVendor advisory
  9. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  10. 2026-10-02 14:49 UTCVendor advisory
  11. 2026-10-02 01:20 UTCEG score recompute
  12. 2026-10-02 01:20 UTCVendor advisory
  13. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  14. 2026-10-01 10:29 UTCVendor advisory
  15. 2026-09-30 21:18 UTCEG score recompute
  16. 2026-09-30 21:18 UTCVendor advisory
  17. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  18. 2026-09-30 08:08 UTCEG score recompute
  19. 2026-09-30 08:08 UTCVendor advisory
  20. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  21. 2026-09-28 21:37 UTCEG score recompute
  22. 2026-09-28 21:37 UTCVendor advisory
  23. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  24. 2026-09-28 05:14 UTCVendor advisory
  25. 2026-09-27 16:03 UTCEG score recompute
  26. 2026-09-27 16:03 UTCVendor advisory
  27. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  28. 2026-09-27 02:53 UTCEG score recompute
  29. 2026-09-27 02:53 UTCVendor advisory
  30. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  31. 2026-09-25 17:22 UTCVendor advisory
  32. 2026-09-25 00:40 UTCEG score recompute
  33. 2026-09-25 00:40 UTCVendor advisory
  34. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  35. 2026-09-24 11:15 UTCVendor advisory
  36. 2026-09-23 22:05 UTCEG score recompute
  37. 2026-09-23 22:05 UTCVendor advisory
  38. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  39. 2026-09-23 08:55 UTCVendor advisory
  40. 2026-09-22 19:45 UTCEG score recompute
  41. 2026-09-22 19:45 UTCVendor advisory
  42. 2026-09-22 04:36 UTCEG score recompute
  43. 2026-09-22 04:36 UTCVendor advisory
  44. 2026-09-21 15:21 UTCVendor advisory
  45. 2026-09-21 01:47 UTCEG score recompute
  46. 2026-09-21 01:47 UTCVendor advisory
  47. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  48. 2026-09-20 12:37 UTCVendor advisory
  49. 2026-09-19 23:22 UTCEG score recompute
  50. 2026-09-19 23:22 UTCVendor advisory
  51. 2026-09-19 10:11 UTCVendor advisory
  52. 2026-09-18 20:19 UTCEG score recompute
  53. 2026-09-18 20:19 UTCVendor advisory
  54. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  55. 2026-09-18 11:17 UTCVendor advisory
  56. 2026-09-17 22:06 UTCEG score recompute
  57. 2026-09-17 22:06 UTCVendor advisory
  58. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  59. 2026-09-17 08:55 UTCVendor advisory
  60. 2026-09-16 19:44 UTCEG score recompute
  61. 2026-09-16 19:44 UTCVendor advisory
  62. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  63. 2026-09-16 05:39 UTCEG score recompute
  64. 2026-09-16 05:39 UTCVendor advisory
  65. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  66. 2026-09-15 16:29 UTCVendor advisory
  67. 2026-09-15 03:18 UTCEG score recompute
  68. 2026-09-15 03:18 UTCVendor advisory
  69. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  70. 2026-09-14 14:07 UTCVendor advisory
  71. 2026-09-14 00:56 UTCEG score recompute
  72. 2026-09-14 00:56 UTCVendor advisory

Related CVEs(same product + same vendor + same CWE)

Same vendor

1 shown

redhat:RHSA-2026:59419

Frequently asked(5)

What is CVE-2026-55893?
CVE-2026-55893 is a high-severity vulnerability; its CVE record was 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 the CVE record for CVE-2026-55893 published?
The CVE record for CVE-2026-55893 was published on August 20, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of September 18, 2026; the record at its source may have been updated since.
Is CVE-2026-55893 actively exploited?
CVE-2026-55893 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (7th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-55893?
CVE-2026-55893 has a CVSS base score of 7.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-55893?
A fix for CVE-2026-55893 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-55893 are linked in the Vendor Advisories panel on this page.

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