Description
Capstone is a disassembly framework. Versions prior to 6.0.0-Alpha8 and 5.0.8 have a NULL pointer dereference in `modRMRequired()` and `decode()` when disassembling 3DNow! opcodes (`0F 0F`) in builds compiled with `-DCAPSTONE_X86_REDUCE`, allowing a remote attacker to crash any application using the reduced X86 Capstone library by supplying a crafted input containing the 4-byte sequence `0F 0F <modrm> <imm8>`. Versions 6.0.0-Alpha8 and 5.0.8 patch the issue.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| capstone-engine | capstone | < 5.0.8, < 6.0.0-Alpha8 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | capstone | 5.0.9-1 | — |
| Debian 13 | capstone | No fix yet | — |
| Debian 12 | capstone | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | capstone | No fix yet | — |
| Ubuntu 26.04 LTS | capstone | No fix yet | — |
| Ubuntu 24.04 LTS | capstone | No fix yet | — |
| Ubuntu 22.04 LTS | capstone | No fix yet | — |
| Ubuntu 20.04 LTS | capstone | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | capstone | No fix yet | — |
| Ubuntu 16.04 LTS | capstone | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Hardened Images 1 | capstone +4 | 5.0.8-0.1.hum1 | RHSA-2026:43841 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | capstone | 5.0.8-r0 | — |
| Alpine v3.23 | capstone | 5.0.8-r0 | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | capstone | No fix yet | — |
| Azure Linux 3 | rust | 1.90.0-10 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | capstone | < 5.0.8 | 5.0.8 | PYSEC-2026-3544 |
Advisories 1
- RHSA-2026:43841 Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update Red Hat Security Advisories (RHSA) · Oct 6, 2026
References
- https://github.com/capstone-engine/capstone/security/advisories/GHSA-289w-cm54-fgrm
- https://github.com/capstone-engine/capstone/pull/2924
- https://github.com/capstone-engine/capstone/commit/a0201371719b5aaa91d318ab2898843718f92d1f
- https://github.com/capstone-engine/capstone/commit/fab595205fee206f5c21be6ed8ad2eaf9225f1c7