Heap overflow and out-of-bounds read in VeraCrypt deserialization
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- High
- Attack requirements
- Present
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-787 and the CVSS impact.
Summary
VeraCrypt before 1.26.30 accepts untrusted length and count values when deserializing data on Unix, macOS, and FreeBSD. These values can overflow a heap allocation or read beyond a buffer (CWE-787), and can also exhaust memory. A local user with low privileges can reach this path through the unprivileged GUI or CLI, which passes data to the root CoreService helper. The source describes this as a local defense-in-depth boundary rather than a remote attack.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
VeraCrypt provides disk encryption with strong security based on TrueCrypt. Prior to 1.26.30, the Unix, macOS, and FreeBSD serialization paths in src/Platform/Serializer.cpp and src/Volume/VolumePassword.cpp accept untrusted length and count values when deserializing data that can cross from the unprivileged GUI or CLI to the root CoreService helper. Serializer::DeserializeWString allocates floor(size / sizeof(wchar_t)) elements but reads size bytes, so a non-aligned size can overflow the heap allocation. VolumePassword::Deserialize accepts PasswordSize values larger than the fixed 128-byte PasswordBuffer, allowing downstream DataPtr() and Size() consumers such as the KDF to read beyond the buffer. DeserializeString, DeserializeWString, and the string and wide-string list readers also lack allocation and collection bounds, which can exhaust memory, and a zero-length DeserializeString can access an empty vector. Windows uses a different path, and the immediate CoreService pipe writer is the same-user parent process, so the documented exposure is a local defense-in-depth boundary rather than a remote attack. This issue is fixed in 1.26.30.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Update VeraCrypt to version 1.26.30, which fixes this issue.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA VeraCrypt (veracrypt) Fixed in 1.26.30
Vendor assessments
Timeline
- 2026-11-04 Threatist record created from CVE-2026-77372
- 2026-11-06 Priority changed: MEDIUM → LOW
- 2026-11-06 Affected versions changed · Red Hat
- 2026-11-06 CVSS score added · Red Hat
References
More veracrypt vulnerabilities
- TI-2026-38769 VeraCryp: wolfCrypt backend bypasses VeraCrypt PBKDF2 iteration count (non-default WOLFCRYPT=1 builds) CVSS 3.1MEDIUM 6.2
- TI-2026-39004 VeraCrypt: Hidden volume quick format weakens plausible deniability CVSS 4.0MEDIUM 4.6
- TI-2026-74032 Missing authorization in VeraCrypt driver exposes disk metadata CVSS 3.1LOW 3.3
Sources
- CVE-2026-77372 · CVE Program
- CVE-2026-77372 · NVD
- FIRST EPSS
- CVE-2026-77372 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences