CVE catalog

CVE-2026-55893

Severity: High · CVSS 7.3CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Published: Aug 20, 2026, 9:32:46 PM UTC
Updated: Aug 20, 2026, 10:17:22 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.19% · Oct 25, 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 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.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	capstone	sid	`5.0.9-1`	vulnerable
Debian	capstone	forky	`5.0.9-1`	vulnerable
Debian	capstone	trixie	`5.0.7-1~deb13u1`	vulnerable
Debian	capstone	bookworm	`4.0.2-5`	vulnerable

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	capstone	source	sid	`(unfixed)`	not yet assigned	Not reported	[1145195]
Debian	capstone	source	forky	`(unfixed)`	not yet assigned	Not reported	[1145195]
Debian	capstone	source	trixie	`(unfixed)`	not yet assigned	Not reported	[1145195]
Debian	capstone	source	bookworm	`(unfixed)`	not yet assigned	Not reported	[1145195]

[Debian bug #1145195]

Notes

[trixie] capstone: Minor issue [bookworm] capstone: Minor issue

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[capstone-tool]Affected
Source package: [capstone]
Details (2)
- 4.0.2-5 · amd64 · bookworm
  Affected
  nvd · capstone · debian · bookworm; nvd · capstone · debian · 12
- 4.0.2-5 · arm64 · bookworm
  Affected
  nvd · capstone · debian · bookworm; nvd · capstone · debian · 12
[libcapstone4]Affected
Source package: [capstone]
Details (2)
- 4.0.2-5 · amd64 · bookworm
  Affected
  nvd · capstone · debian · bookworm; nvd · capstone · debian · 12
- 4.0.2-5 · arm64 · bookworm
  Affected
  nvd · capstone · debian · bookworm; nvd · capstone · debian · 12
[libcapstone-dev]Affected
Source package: [capstone]
Details (2)
- 4.0.2-5 · amd64 · bookworm
  Affected
  nvd · capstone · debian · bookworm; nvd · capstone · debian · 12
- 4.0.2-5 · arm64 · bookworm
  Affected
  nvd · capstone · debian · bookworm; nvd · capstone · debian · 12
[python3-capstone]Affected
Source package: [capstone]
Details (2)
- 4.0.2-5 · amd64 · bookworm
  Affected
  nvd · capstone · debian · bookworm; nvd · capstone · debian · 12
- 4.0.2-5 · arm64 · bookworm
  Affected
  nvd · capstone · debian · bookworm; nvd · capstone · debian · 12

[Debian 13 (Trixie)]

[capstone-tool]Affected
Source package: [capstone]
Details (2)
- 5.0.7-1~deb13u1 · amd64 · trixie
  Affected
  nvd · capstone · debian · 13
- 5.0.7-1~deb13u1 · arm64 · trixie
  Affected
  nvd · capstone · debian · 13
[libcapstone5]Affected
Source package: [capstone]
Details (2)
- 5.0.7-1~deb13u1 · amd64 · trixie
  Affected
  nvd · capstone · debian · 13
- 5.0.7-1~deb13u1 · arm64 · trixie
  Affected
  nvd · capstone · debian · 13
[libcapstone-dev]Affected
Source package: [capstone]
Details (2)
- 5.0.7-1~deb13u1 · amd64 · trixie
  Affected
  nvd · capstone · debian · 13
- 5.0.7-1~deb13u1 · arm64 · trixie
  Affected
  nvd · capstone · debian · 13
[python3-capstone]Affected
Source package: [capstone]
Details (2)
- 5.0.7-1~deb13u1 · amd64 · trixie
  Affected
  nvd · capstone · debian · 13
- 5.0.7-1~deb13u1 · arm64 · trixie
  Affected
  nvd · capstone · debian · 13

Observed: Oct 23, 2026, 9:38:35 PM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]