Memory over-allocation in evm crate

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2021-29511: 1.28% estimated exploitation activity in the next 30 days; percentile 70.05 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact Prior to the patch, when executing specific EVM opcodes related to memory operations that use evmcore::Memory::copylarge, the crate can over-allocate memory when it is not needed, making it possible for an attacker to perform denial-of-service attack. Patches The flaw was corrected in commit 19ade85. Users should upgrade to ==0.21.1, ==0.23.1, ==0.24.1, ==0.25.1, =0.26.1. Workarounds None. Please upgrade your evm crate version References Fix commit: https://github.com/rust-blockchain/evm/commit/19ade858c430ab13eb562764a870ac9f8506f8dd For more information If you have any questions or comments about this advisory: Open an issue in evm repo Email Wei

Published by the source

30 Jan 2024, 23:55 UTC

Last modified by the source

30 Jan 2024, 23:55 UTC

Source last checked

26 Oct 2026, 15:38 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-4jwq-572w-4388

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# Patch Next advisory brief: CVE-2021-29511

Advisory: Memory over-allocation in evm crate
IDs: CVE-2021-29511, GHSA-4jwq-572w-4388
Record: https://patchnext.com/advisories/cve-2021-29511 (revision 1, source checked 26 Oct 2026, 15:38 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: evm-core 0.26.1, 0.25.1, 0.24.1, 0.23.1, 0.22.1, 0.21.1; evm 0.26.1, 0.25.1, 0.24.1, 0.23.1, 0.22.1, 0.21.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io evm-core: affected <= 0.21.0; >= 0.22.0, <= 0.22.0; >= 0.23.0, <= 0.23.0; >= 0.24.0, <= 0.24.0; >= 0.25.0, <= 0.25.0; >= 0.26.0, <= 0.26.0; fixed in 0.25.1, 0.22.1, 0.24.1, 0.23.1, 0.26.1, 0.21.1
- crates.io evm: affected <= 0.21.0; >= 0.22.0, <= 0.22.0; >= 0.23.0, <= 0.23.0; >= 0.24.0, <= 0.24.0; >= 0.25.0, <= 0.25.0; >= 0.26.0, <= 0.26.0; fixed in 0.25.1, 0.22.1, 0.24.1, 0.23.1, 0.26.1, 0.21.1

## Suggested inspection (read-only)
- crates.io evm-core: check the installed version with your package manager.
- crates.io evm: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on evm-core, evm.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-4jwq-572w-4388 (GitHub-reviewed advisory GHSA-4jwq-572w-4388 lists affected ranges: crates.io evm >=0 =0.22.0 =0.23.0 =0.24.0 =0.25.0 =0.26.0 =0 =0.22.0 =0.23.0 =0.24.0 =0.25.0 =0.26.0 <=0.26.0)

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