rs-soroban-sdk: Always-Incorrect Control Flow Implementation
CVE-2026-26267 is a high-severity always-incorrect control flow implementation vulnerability in rs-soroban-sdk from Stellar, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected rs-soroban-sdk versions: >= 25.0.0, < 25.1.1; >= 23.0.0, < 23.5.2; < 22.0.10. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.36% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of rs-soroban-sdk you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Stellar | rs-soroban-sdk | >= 25.0.0, < 25.1.1; >= 23.0.0, < 23.5.2; < 22.0.10 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. Scored by CNA (github.com).
Official description
soroban-sdk is a Rust SDK for Soroban contracts. Prior to versions 22.0.10, 23.5.2, and 25.1.1, the `#[contractimpl]` macro contains a bug in how it wires up function calls. `#[contractimpl]` generates code that uses `MyContract::value()` style calls even when it's processing the trait version. This means if an inherent function is also defined with the same name, the inherent function gets called instead of the trait function. This means the Wasm-exported entry point silently calls the wrong function when two conditions are met simultaneously: First, an `impl Trait for MyContract` block is defined with one or more functions, with `#[contractimpl]` applied. Second, an `impl MyContract` block is defined with one or more identically named functions, without `#[contractimpl]` applied. If the trait version contains important security checks, such as verifying the caller is authorized, that the inherent version does not, those checks are bypassed. Anyone interacting with the contract through its public interface will call the wrong function. The problem is patched in `soroban-sdk-macros` versions 22.0.10, 23.5.2, and 25.1.1. The fix changes the generated call from `<Type>::func()` to `<Type as Trait>::func()` when processing trait implementations, ensuring Rust resolves to the trait associated function regardless of whether an inherent function with the same name exists. Users should upgrade to `soroban-sdk-macros` 22.0.10, 23.5.2, or 25.1.1 and recompile their contracts. If upgrading is not immediately possible, contract developers can avoid the issue by ensuring that no inherent associated function on the contract type shares a name with any function in the trait implementation. Renaming or removing the conflicting inherent function eliminates the ambiguity and causes the macro-generated code to correctly resolve to the trait function.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Always-Incorrect Control Flow Implementation
The code contains a control flow path that does not reflect the algorithm that the path is intended to implement, leading to incorrect behavior any time this path is navigated.
More Always-Incorrect Control Flow Implementation vulnerabilities (CWE-670)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Always-Incorrect Control Flow Implementation vulnerabilities
- 9.8 Critical severity
- 8.2 High severity
- 9.1 Critical severity
- 7.5 High severity
- 7.1 High severity
- 7.5 High severity
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