# CVE-2026-77372: VeraCrypt: Heap overflow and out-of-bounds read in Serializable deserialization (elevated Core service input path)

Status: published. Published: 2026-11-04. Updated: 2026-11-04.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- veracrypt / VeraCrypt: < 1.26.30 (affected). Source: CNA: GitHub_M

## Severity and prioritization

- CVSS 4.0: 8.8 (high); CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H; source: CNA: GitHub_M

- CVSS 4.0: 8.8 (high); CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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; source: NVD: security-advisories@github.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-125, CWE-787

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/veracrypt/VeraCrypt/security/advisories/GHSA-4j3p-7hp7-xw73 (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/veracrypt/VeraCrypt/commit/fb9d96c52dace4d34c5427402b512e8de5f832d6 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/veracrypt/VeraCrypt/releases/tag/VeraCrypt_1.26.30 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/veracrypt/VeraCrypt/commit/fb9d96c52dace4d34c5427402b512e8de5f832d6 (security-advisories@github.com)

- https://github.com/veracrypt/VeraCrypt/releases/tag/VeraCrypt_1.26.30 (security-advisories@github.com)

- https://github.com/veracrypt/VeraCrypt/security/advisories/GHSA-4j3p-7hp7-xw73 (security-advisories@github.com)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-77372; retrieved 2026-11-04; source updated 2026-11-04

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-77372; retrieved 2026-11-05; source updated 2026-11-04

Revision: 8078b878a614f6322ca5f56826ffb32af8c9cdc68ba879e7d07fbc350850b4ff

Canonical: https://y2.dev/cve/CVE-2026-77372

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