https://cve.radiocsirt.org/rss/recent/all/10 Most recent entries from all 2026-10-03T00:46:58.027653+00:00 Vulnerability-Lookup csirt@opendfir.org python-feedgen Contains only the most 10 recent entries. https://cve.radiocsirt.org/vuln/cve-2025-21607 CVE-2025-21607 — Success of Certain Precompile Calls not Checked in Vyper 2026-10-03T00:46:58.062546+00:00

Affected: vyperlang vyper

Vyper is a Pythonic Smart Contract Language for the EVM. When the Vyper Compiler uses the precompiles EcRecover (0x1) and Identity (0x4), the success flag of the call is not checked. As a consequence an attacker can provide a specific amount of gas to make these calls fail but let the overall execution continue. Then the execution result can be incorrect. Based on EVM's rules, after the failed precompile the remaining code has only 1/64 of the pre-call-gas left (as 63/64 were forwarded and spent). Hence, only fairly simple executions can follow the failed precompile calls. Therefore, we found no significantly impacted real-world contracts. None the less an advisory has been made out of an abundance of caution. This issue is fixed in 0.4.1.

 https://cve.radiocsirt.org/vuln/ghsa-vgf2-gvx8-xwc3 GHSA-vgf2-gvx8-xwc3 — Vyper Does Not Check the Success of Certain Precompile Calls 2026-10-03T00:46:58.062619+00:00

Affected: PyPI: vyper

### Summary

When the Vyper Compiler uses the precompiles EcRecover (0x1) and Identity (0x4), the success flag of the call is not checked. As a consequence an attacker can provide a specific amount of gas to make these calls fail but let the overall execution continue. Then the execution result can be incorrect.

Based on EVM's rules, after the failed precompile the remaining code has only 1/64 of the pre-call-gas left (as 63/64 were forwarded and spent). Hence, only fairly simple executions can follow the failed precompile calls. Therefore, we found no significantly impacted real-world contracts.

The fix is tracked in https://github.com/vyperlang/vyper/pull/4451.

### Details

#### The relevant precompiles

##### EcRecover

EcRecover is used in vyper's `ecrecover` built-in. As the precompile consumes 3000 gas, any execution after an out-of-gas EcRecover call has at most 47 gas left.

##### Identity

- The Identity precompile is used in vyper to perform memory copy operations. As its cost is variable, a variable amount of gas might be left after a failed call. The bigger the copy operation, the more gas can be left. Hence, a failed call to Identity could theoretically be followed by successful storage changes or emitted events. - Identity is no longer used when `evm-version` `cancun` is used (because `MCOPY` is used instead). In 0.4.0 `cancun` is default, in 0.3.10 `cancun` is an option, otherwise `cancun` is not available. As only pre-`cancun` versions are relevant, we do…