CVE-2026-55406: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor in anthropics buffa
Buffa is a pure-Rust Protocol Buffers implementation with first-class protobuf editions support. Prior to 0.7.0, a soundness bug in the OwnedView<V> type allowed safe Rust code to trigger a use-after-free: the OwnedView::decode constructor transmuted a borrowed slice to &'static [u8], and the Deref implementation exposed the promoted 'static lifetime on borrowed view fields (such as &'static str and &'static [u8]) to callers, so the borrow checker permitted those references to outlive the OwnedView; once the OwnedView was dropped and its backing buffer freed, the references became dangling, enabling memory corruption, information disclosure of freed heap contents, and cross-thread misuse without any unsafe code in the calling application. This issue is fixed in version 0.7.0.
AI Analysis
Technical Summary
CVE-2026-55406 describes a vulnerability in anthropics' buffa library before version 0.7.0 where the OwnedView::decode constructor unsafely transmuted a borrowed slice to a 'static lifetime reference. This caused the Rust borrow checker to allow references to outlive the OwnedView instance, resulting in use-after-free conditions. Exploitation can lead to memory corruption, exposure of freed heap data, and cross-thread misuse, all achievable without unsafe code in the calling application. The vulnerability is addressed by a fix in version 0.7.0.
Potential Impact
The vulnerability enables memory corruption and disclosure of sensitive information from freed heap memory. It also allows cross-thread misuse of dangling references. These impacts arise from use-after-free conditions in safe Rust code, potentially compromising application stability and confidentiality.
Mitigation Recommendations
A fix is available in buffa version 0.7.0. Users should upgrade to version 0.7.0 or later to remediate this vulnerability. No vendor advisory contradicts this; therefore, upgrading is the recommended mitigation.
CVE-2026-55406: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor in anthropics buffa
Description
Buffa is a pure-Rust Protocol Buffers implementation with first-class protobuf editions support. Prior to 0.7.0, a soundness bug in the OwnedView<V> type allowed safe Rust code to trigger a use-after-free: the OwnedView::decode constructor transmuted a borrowed slice to &'static [u8], and the Deref implementation exposed the promoted 'static lifetime on borrowed view fields (such as &'static str and &'static [u8]) to callers, so the borrow checker permitted those references to outlive the OwnedView; once the OwnedView was dropped and its backing buffer freed, the references became dangling, enabling memory corruption, information disclosure of freed heap contents, and cross-thread misuse without any unsafe code in the calling application. This issue is fixed in version 0.7.0.
CVSS v4.0
Score 5.9medium
Affected software
pkg:cargo/github/anthropics/buffaRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-55406 describes a vulnerability in anthropics' buffa library before version 0.7.0 where the OwnedView::decode constructor unsafely transmuted a borrowed slice to a 'static lifetime reference. This caused the Rust borrow checker to allow references to outlive the OwnedView instance, resulting in use-after-free conditions. Exploitation can lead to memory corruption, exposure of freed heap data, and cross-thread misuse, all achievable without unsafe code in the calling application. The vulnerability is addressed by a fix in version 0.7.0.
Potential Impact
The vulnerability enables memory corruption and disclosure of sensitive information from freed heap memory. It also allows cross-thread misuse of dangling references. These impacts arise from use-after-free conditions in safe Rust code, potentially compromising application stability and confidentiality.
Mitigation Recommendations
A fix is available in buffa version 0.7.0. Users should upgrade to version 0.7.0 or later to remediate this vulnerability. No vendor advisory contradicts this; therefore, upgrading is the recommended mitigation.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-16T21:48:43.124Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a5907ce68715ace4356ca7c
Added to database: 07/16/2026, 16:33:18 UTC
Last enriched: 07/16/2026, 16:48:43 UTC
Last updated: 07/16/2026, 18:57:25 UTC
Views: 7
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