Anchor: `InterfaceAccount` allows account substitution between unexpected types

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

### Impact Any uses of `InterfaceAccount` allows another unexpected account type to be passed, after https://github.com/solana-foundation/anchor/pull/3837 disabled discriminator checking for this type. The bug was originally reported and fixed in https://github.com/solana-foundation/anchor/pull/4139, see that PR for more details. ### Patches https://github.com/solana-foundation/anchor/pull/4139 patched the issue and was released in `1.0.0-rc.2`. Users should upgrade to the latest released version of Anchor 1.0. ### References Bug landed in: https://github.com/solana-foundation/anchor/pull/3837 Bug fixed in: https://github.com/solana-foundation/anchor/pull/4139

Source published

13 May 2026 15:33:46 UTC

Source modified

19 May 2026 20:30:23 UTC

Observed here

24 Oct 2026 13:19:54 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

Publisher rating · HIGH

Affected versions of `anchor-lang` allowed `InterfaceAccount` to accept accounts with an unexpected Anchor discriminator. A change to `InterfaceAccount` caused checked deserialization to be bypassed for this account wrapper, so validation proved only that the account owner matched one of the accepted interface owners. It did not prove that the account data belonged to the expected account type. Programs using `InterfaceAccount` rely on Anchor to enforce both owner and account-type validation before the handler runs. With discriminator checking disabled, an attacker could pass another account type owned by an accepted program and have it deserialized through the expected interface wrapper. This could bypass account-type assumptions made by the program and lead to incorrect authorization or state handling. The issue was fixed in `anchor-lang` 1.0.0-rc.2 by restoring checked deserialization for `InterfaceAccount::try_from`, while keeping explicitly unchecked behavior available only through the unchecked API. Users should upgrade to `anchor-lang` 1.0.0-rc.2 or later.

Source published

8 May 2026 12:00:00 UTC

Source modified

12 Oct 2026 18:00:08 UTC

Observed here

24 Oct 2026 13:19:54 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N