---
id: "CVE-2026-77372"
kind: "vulnerability"
aliases: ["CVE-2026-77372"]
title: "VeraCrypt: crafted serialized input overflows heap in root helper"
severity: "high"
cvss: 8.8
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["disk-encryption", "freebsd", "linux", "macos", "package", "veracrypt"]
not_affected_if: ["version-1.26.30-or-later", "windows-only"]
published_at: "2026-11-04T23:17:58+00:00"
first_seen_at: "2026-11-05T00:31:00+00:00"
updated_at: "2026-11-05T00:31:42+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-77372", "first_seen_at": "2026-11-05T00:31:00+00:00"}]
exploit_sources: []
---

# VeraCrypt: crafted serialized input overflows heap in root helper

VeraCrypt's Unix, macOS and FreeBSD code that passes data from the unprivileged GUI or CLI to the root CoreService helper accepts unchecked length and count values, so a non-aligned string size can overflow a heap buffer and an oversized password size can read past a fixed 128-byte buffer. An attacker who can feed that boundary could crash the helper, exhaust memory, or read adjacent memory in a privileged process.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed VeraCrypt version with `veracrypt --version` on Linux or macOS, or the About dialog in the GUI.
- Look for the CoreService helper running as root on Unix, macOS or FreeBSD systems where VeraCrypt is installed.

## Fix

- VeraCrypt: move to `1.26.30` or later.

## Timeline

- 2026-11-05T00:31:00+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-77372

## Documents

- [advisory] Vendor advisory: github.com https://github.com/veracrypt/VeraCrypt/security/advisories/GHSA-4j3p-7hp7-xw73
- [fix] Patch: github.com https://github.com/veracrypt/VeraCrypt/commit/fb9d96c52dace4d34c5427402b512e8de5f832d6
- [fix] Release notes: github.com https://github.com/veracrypt/VeraCrypt/releases/tag/VeraCrypt_1.26.30

## From the sources

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.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_