CVE-2025-47774
Vyper is the Pythonic Programming Language for the Ethereum Virtual Machine. In versions up to and including 0.4.2rc1, the `slice()` builtin can elide side effects when the output length is 0, and the source bytestring is a builtin (`msg.data` or `<address>.code`). The reason is that for these source locations, the check that `length >= 1` is skipped. The result is that a 0-length bytestring constructed with slice can be passed to `make_byte_array_copier`, which elides evaluation of its source argument when the max length is 0. The impact is that side effects in the `start` argument may be elided when the `length` argument is 0, e.g. `slice(msg.data, self.do_side_effect(), 0)`. The fix in pull request 4645 disallows any invocation of `slice()` with length 0, including for the ad hoc locations discussed in this advisory. The fix is expected to be part of version 0.4.2.
Scoring
- Severity
- LOW
- CVSS base score
- 2.9
- CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P
- EPSS probability
- 0.46%
- CWE
- CWE-691
- Published
- 2025-05-15
- Last modified
- 2026-03-13
Affected products
- vyperlang vyper
Weakness type
Related vulnerabilities
- CVE-2026-20276 — Cisco IOS XR Software Security Hardening Release: September 2026
- CVE-2026-79033 — Insufficient control flow management in DevTools in Google Chrome prior to 152.0.7977.65 allowed a...
- CVE-2026-20271 — Cisco IOS XE Software Security Hardening Release
- CVE-2026-5938 — Foxit PDF Editor/Reader Infinite Loop Denial-of-Service Vulnerability
- CVE-2025-35963 — Insufficient control flow management for some Intel(R) PROSet/Wireless WiFi Software for Windows...
- CVE-2025-25273 — Insufficient control flow management in the Linux kernel-mode driver for some Intel(R) 700 Series...
- CVE-2025-24305 — Insufficient control flow management in the Alias Checking Trusted Module (ACTM) firmware for some...
- CVE-2025-22893 — Insufficient control flow management in the Linux kernel-mode driver for some Intel(R) 800 Series...