CVE-2026-55406

MEDIUMPre-NVD 5.95.9
EchelonGraph scoreLOW confidence

This medium-severity CVE scores 5.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: secondary
Trending — 3 sources updated this week
5.9
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.9Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 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 v3
5.9
EG Score
5.9(low)
EG Risk
—
EPSS
2.8%
KEV
Not listed

Published

July 16, 2026

Last Modified

July 16, 2026

Advisory Details (4)

Auto-updated Jul 16, 2026
Patch available. Sources: github, github_pr, github_commit, github_release.
github_release Patch Available

v0.7.0

Patch available: anthropics/buffa v0.7.0

https://github.com/anthropics/buffa/releases/tag/v0.7.0
github_commit

commit 7dcf50a1a40e (anthropics/buffa)

Fix landed in anthropics/buffa commit 7dcf50a1a40e — awaiting tagged release

https://github.com/anthropics/buffa/commit/7dcf50a1a40eca6ed8d6c6dd59f4310aa0d68b0e
github_pr

OwnedView: remove Deref, add generated FooOwnedView accessor wrappers

Fix merged in anthropics/buffa PR #154 on 2026-05-28 — awaiting tagged release

https://github.com/anthropics/buffa/pull/154
github Patch Available

Use-After-Free in OwnedView via Unsound 'static Lifetime Promotion in Deref · Advisory · anthropics/buffa · GitHub

https://github.com/anthropics/buffa/security/advisories/GHSA-9pwq-gcrx-wghh

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 9× in last 7d / 9× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-21 15:25 UTCEPSS rescore
  3. 2026-07-20 17:08 UTCEPSS rescore
  4. 2026-07-19 14:31 UTCEPSS rescore
  5. 2026-07-19 14:31 UTCEPSS rescore
  6. 2026-07-19 02:29 UTCEPSS rescore
  7. 2026-07-18 10:04 UTCEPSS rescore
  8. 2026-07-16 16:30 UTCEG score recompute
  9. 2026-07-16 16:28 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-55406?
CVE-2026-55406 is a medium vulnerability published on July 16, 2026. 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…
When was CVE-2026-55406 disclosed?
CVE-2026-55406 was first published in the National Vulnerability Database on July 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55406 actively exploited?
CVE-2026-55406 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-55406?
CVE-2026-55406 has a CVSS v3 base score of 5.9 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-55406?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55406, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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