CVE-2026-55406
Buffa: Use-After-Free in OwnedView via Unsound 'static Lifetime Promotion in Deref
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Timeline
ID reserved
By GitHub_M
- 30 days later
· 30 days later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 4.0 | Medium5.9 | CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N |
| NVDNVD · Deferred | 4.0 | Medium5.9 | CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.19% · top 91% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.9.
Weakness
Affected products
- affected < 0.7.0
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- crates.iobuffaGHSA-9pwq-gcrx-wghh (opens in a new tab)
References (4)
- https://github.com/anthropics/buffa/security/advisories/GHSA-9pwq-gcrx-wghh (opens in a new tab)x_refsource_CONFIRM
- https://github.com/anthropics/buffa/pull/154 (opens in a new tab)x_refsource_MISC
- https://github.com/anthropics/buffa/commit/7dcf50a1a40eca6ed8d6c6dd59f4310aa0d68b0e (opens in a new tab)x_refsource_MISC
- https://github.com/anthropics/buffa/releases/tag/v0.7.0 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-9pwq-gcrx-wghh (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-55406)Record last updated .