CVE WatchAug 20, 2026

CVE-2026-64846

Nix is a package manager for Linux and other Unix systems. Prior to 2.35.0, a malicious derivation executed with the recursive-nix experimen

CVSS

2.8

Low

EPSS

—

KEV

—

Exploit Today

—

0-100

Published: Aug 20, 2026 · Last modified: Aug 20, 2026 · CWE-61 · CWE-367

EPSS · 30d

Not enough EPSS history yet.

Technical description

Nix is a package manager for Linux and other Unix systems. Prior to 2.35.0, a malicious derivation executed with the recursive-nix experimental feature can exploit a time-of-check/time-of-use race involving final symlink handling in the LocalStore restore path. The race can cause writeFile to follow a substituted final symlink when opening a path with O_TRUNC instead of enforcing FinalSymlink::DontFollow, allowing the Nix process or nix-daemon to create or truncate an empty file outside the build sandbox with the daemon user's permissions. The primitive does not provide arbitrary-content writes and requires winning the race. This issue is fixed in version 2.35.0.

Official references

Related CVEs

CVECVSSEPSSKEVRExploitTitleMod.

CVE-2026-169277.3 HIG

—

———IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a local attacker to gain root privileges due to a time-of-check to time-of-use (TOCTOU) race condition.3h CVE-2026-169227.0 HIG

—

———IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a local attacker to execute arbitrary code due to a time-of-check to time-of-use (TOCTOU) race condition.3h CVE-2026-168387.0 HIG

—

——0IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a local attacker to overwrite critical files and obtain sensitive information due to a time-of-check to time-of-use (TOCTOU) race condition.7h CVE-2026-73829—

—

——0Time-of-check Time-of-use (TOCTOU) Race Condition in ZenHive mpp allows an unauthenticated remote client to redeem one confirmed on-chain payment for multiple paid-resource accesses. The type="hash" credential path in MPP.Methods.Tempo.verify/2 guards against replay with a non-atomic check-then-mark sequence: check_hash_unused/2 reads the dedup store, an eth_getTransactionReceipt round trip verifies the payment on chain, and only then does mark_hash_used/2 write the mark. Concurrent requests carrying the same settled payment hash all pass the read before any of them writes, so each is issued a receipt. The store's atomic check_and_mark/2 primitive is available and used by the type="transaction" path, but the hash path calls plain get and put even when the configured store implements it. Exploitation requires a dedup store to be configured; the default nil store is stateless and documented as offering no replay protection at all. This issue affects mpp: from 0.2.0 before 0.6.1.7h CVE-2024-139427.6 HIG

—

——0Secure BootROM of RK3588s SoC is vulnerable to a time-of-check to time-of-use attack in case of booting from external media (SPI NOR or NAND, EMMC or SD). The code reads the header of the next-stage loader twice. The header contains hashes of the executable modules and is signed with a private key, the public part of which is verified against the SHA256 digest blown in the OTP. The first read is only partial and contains only the hashes of the executable modules. The second is complete, including the header signature. Although the header is verified based on the fully read data, the authenticity of the executable modules is checked against the partial data from the first read. An attacker with physical access to a device containing RK3588s SoC can easily modify the next-stage loader data on-the-fly using a low-cost SD-card or SPI NOR/NAND or EMMC emulator. Even a simple ultra low-cost circuit comprising two memory chips (containing the same data but different headers - the original and the modified one) and a multiplexer can be used to carry out an attack. This can lead to arbitrary code execution with the highest privileges available (EL3). This issue affects RK3588s: RK3588s SoC BootROM (secure) 350B20210512V100 and possibly others. As remediation apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable https://www.rock-chips.com/a/en/products/RK35_Series/2022/0926/1660.html1d CVE-2026-168197.7 HIG

—

——0IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a local attacker to cause a denial of service and compromise data integrity due to a time-of-check time-of-use race condition.4h