CVE-2026-118769
Botan: Integer overflow when reporting block size in FFI can cause memory corruption
Botan is a C++ cryptography library. From 2.1.0 until 3.13.0, the Botan C API function botan_block_cipher_block_size converted a size_t block size to int without a bounds check. In an application that accepts external algorithm parameter strings and uses the FFI raw ECB mode, an attacker can select the variable-block-size Lion cipher so that the reported size is truncated, the caller allocates insufficient memory, and later block processing causes memory corruption. The C++ API and normally used C API modes such as CBC and CTR are unaffected. This issue is fixed in version 3.13.0.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
9.2
Botan: Integer overflow when reporting block size in FFI can cause memory corruption
Botan is a C++ cryptography library. From 2.1.0 until 3.13.0, the Botan C API function botan_block_cipher_block_size converted a size_t block size to int without a bounds check. In an application that accepts external algorithm parameter strings and uses the FFI raw ECB mode, an attacker can select the variable-block-size Lion cipher so that the reported size is truncated, the caller allocates insufficient memory, and later block processing causes memory corruption. The C++ API and normally used C API modes such as CBC and CTR are unaffected. This issue is fixed in version 3.13.0.
- Record
CVE-2026-118769- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-125, CWE-681, CWE-787
- Updated
- 2026-11-02
EUVDEUVD-2026-113278
9.2
Botan is a C++ cryptography library. From 2.1.0 until 3.13.0, the Botan C API function botan_block_cipher_block_size converted a size_t block size to int without a bounds check. In an application that accepts external algorithm parameter strings and uses the FFI raw ECB mode, an attacker can select the variable-block-size Lion cipher so that the reported size is truncated, the caller allocates insufficient memory, and later block processing causes memory corruption. The C++ API and normally used C API modes such as CBC and CTR are unaffected. This issue is fixed in version 3.13.0.
- Record
EUVD-2026-113278- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - Updated
- 2026-11-02
NVD
9.2
Botan is a C++ cryptography library. From 2.1.0 until 3.13.0, the Botan C API function botan_block_cipher_block_size converted a size_t block size to int without a bounds check. In an application that accepts external algorithm parameter strings and uses the FFI raw ECB mode, an attacker can select the variable-block-size Lion cipher so that the reported size is truncated, the caller allocates insufficient memory, and later block processing causes memory corruption. The C++ API and normally used C API modes such as CBC and CTR are unaffected. This issue is fixed in version 3.13.0.
- Record
CVE-2026-118769- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/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 - Weakness
- CWE-125, CWE-681, CWE-787
- Updated
- 2026-11-02
OSV
9.2
Botan: Integer overflow when reporting block size in FFI can cause memory corruption
Botan is a C++ cryptography library. From 2.1.0 until 3.13.0, the Botan C API function botan_block_cipher_block_size converted a size_t block size to int without a bounds check. In an application that accepts external algorithm parameter strings and uses the FFI raw ECB mode, an attacker can select the variable-block-size Lion cipher so that the reported size is truncated, the caller allocates insufficient memory, and later block processing causes memory corruption. The C++ API and normally used C API modes such as CBC and CTR are unaffected. This issue is fixed in version 3.13.0.
- Record
CVE-2026-118769- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-125, CWE-681, CWE-787
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-118769
9.2
Botan is a C++ cryptography library. From 2.1.0 until 3.13.0, the Botan C API function botan_block_cipher_block_size converted a size_t block size to int without a bounds check. In an application that accepts external algorithm parameter strings and uses the FFI raw ECB mode, an attacker can select the variable-block-size Lion cipher so that the reported size is truncated, the caller allocates insufficient memory, and later block processing causes memory corruption. The C++ API and normally used C API modes such as CBC and CTR are unaffected. This issue is fixed in version 3.13.0.
- Record
DEBIAN-CVE-2026-118769- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/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 - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-118769
9.2
Botan is a C++ cryptography library. From 2.1.0 until 3.13.0, the Botan C API function botan_block_cipher_block_size converted a size_t block size to int without a bounds check. In an application that accepts external algorithm parameter strings and uses the FFI raw ECB mode, an attacker can select the variable-block-size Lion cipher so that the reported size is truncated, the caller allocates insufficient memory, and later block processing causes memory corruption. The C++ API and normally used C API modes such as CBC and CTR are unaffected. This issue is fixed in version 3.13.0.
- Record
UBUNTU-CVE-2026-118769- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - Updated
- 2026-11-05
OSVAZL-112409 No score
CVE-2026-118769 affecting package botan2 2.14.0-2
Botan is a C++ cryptography library. From 2.1.0 until 3.13.0, the Botan C API function botan_block_cipher_block_size converted a size_t block size to int without a bounds check. In an application that accepts external algorithm parameter strings and uses the FFI raw ECB mode, an attacker can select the variable-block-size Lion cipher so that the reported size is truncated, the caller allocates insufficient memory, and later block processing causes memory corruption. The C++ API and normally used C API modes such as CBC and CTR are unaffected. This issue is fixed in version 3.13.0.
- Record
AZL-112409- Updated
- 2026-11-05
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
botan2Azure Linux:3 |
through 2.14.0-2 | None known |
botanDebian:12 |
All versions, plus listed versions 2.19.3+dfsg-12.19.3+dfsg-1+deb12u12.19.4+dfsg-12.19.5+dfsg-12.19.5+dfsg-22.19.5+dfsg-32.19.5+dfsg-4 |
None known |
botanDebian:13 |
All versions, plus listed versions 2.19.5+dfsg-4 |
None known |
botan3Debian:13 |
All versions, plus listed versions 3.10.0+dfsg-13.10.0+dfsg-23.11.0+dfsg-13.11.1+dfsg-13.11.1+dfsg-2 Show 10 moreShow less3.12.0+dfsg-13.12.0+dfsg-23.12.0+dfsg-2~deb13u13.13.0+dfsg-13.13.0+dfsg-23.7.1+dfsg-23.8.1+dfsg-13.9.0+dfsg-13.9.0+dfsg-23.9.0+dfsg-2.1 |
None known |
botan3Debian:14 |
before 3.13.0+dfsg-2, plus listed versions 3.10.0+dfsg-13.10.0+dfsg-23.11.0+dfsg-13.11.1+dfsg-13.11.1+dfsg-2 Show 9 moreShow less3.12.0+dfsg-13.12.0+dfsg-23.12.0+dfsg-2~deb13u13.13.0+dfsg-13.7.1+dfsg-23.8.1+dfsg-13.9.0+dfsg-13.9.0+dfsg-23.9.0+dfsg-2.1 |
3.13.0+dfsg-2 |
botanUbuntu:18.04:LTS |
All versions, plus listed versions 2.4.0-32.4.0-42.4.0-5ubuntu1 |
None known |
botanUbuntu:20.04:LTS |
All versions, plus listed versions 2.9.0-22.9.0-2build12.12.1-22.12.1-2build1 |
None known |
botanUbuntu:Pro:22.04:LTS |
All versions, plus listed versions 2.17.3+dfsg-32.19.1+dfsg-2ubuntu12.19.1+dfsg-2ubuntu1+esm1 |
None known |
botanUbuntu:Pro:24.04:LTS |
All versions, plus listed versions 2.19.3+dfsg-1ubuntu12.19.3+dfsg-1ubuntu22.19.3+dfsg-1ubuntu2+esm1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | OSV | |
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-118769 is a critical vulnerability (CVSS 9.2) in Randombit Botan, published October 29, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.36%, the 30th percentile. Fixed in botan3 3.13.0+dfsg-2.
References
github.com/randombit/botan/security/advisories/GHSA-c68p-822g-jfvr
github.com/randombit/botan/pull/5805
github.com/randombit/botan/commit/c6089ab7fab616517d56c447c93e13a5c57a0af3
nvd.nist.gov/vuln/detail/CVE-2026-118769
github.com/CVEProject/cvelistV5/tree/main/cves/2026/118xxx/CVE-2026-118769.json
security-tracker.debian.org/tracker/CVE-2026-118769
ubuntu.com/security/CVE-2026-118769
cve.org/CVERecord?id=CVE-2026-118769