CVE-2026-55406: Buffa has a Use-After-Free in OwnedView via Unsound 'static Lifetime Promotion in Deref
A soundness bug in buffa’s OwnedView<V> 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. Because these references appeared to be 'static, the borrow checker permitted them to outlive the OwnedView; once the OwnedView was dropped and its backing buffer freed, those references became dangling, enabling memory corruption, information disclosure of freed heap contents, and cross-thread misuse — all without any unsafe code in the calling application. Users are advised to update to the latest patched version of buffa.
Thank you to hackerone.com/suul for reporting this issue.
References
- github.com/advisories/GHSA-9pwq-gcrx-wghh
- github.com/anthropics/buffa/commit/7dcf50a1a40eca6ed8d6c6dd59f4310aa0d68b0e
- github.com/anthropics/buffa/pull/154
- github.com/anthropics/buffa/releases/tag/v0.7.0
- github.com/anthropics/buffa/security/advisories/GHSA-9pwq-gcrx-wghh
- nvd.nist.gov/vuln/detail/CVE-2026-55406
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