CVE-2026-55406

MEDIUMPre-NVD 5.95.9—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 91% of all CVEs by exploit prediction. 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: epss, secondary
5.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.9Exploit: None knownExposed: 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(medium)
EG Risk
27(Track)
EG Risk 27/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity59% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
9%
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

Vendor Advisories for CVE-2026-55406(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
crates.io(1)
PackageVulnerable rangeFixed inDependents
buffa—0.7.0—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 44× 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. 2026-09-11 14:53 UTCEPSS rescore
  2. 2026-09-10 09:35 UTCEPSS rescore
  3. 2026-09-08 22:01 UTCEPSS rescore
  4. 2026-09-08 00:30 UTCEG score recompute
  5. 2026-09-07 16:01 UTCEPSS rescore
  6. 2026-09-06 13:47 UTCEPSS rescore
  7. 2026-09-05 20:39 UTCEG score recompute
  8. 2026-09-04 05:06 UTCEPSS rescore
  9. 2026-09-02 14:12 UTCEPSS rescore
  10. 2026-09-01 13:54 UTCEPSS rescore
  11. 2026-09-01 04:40 UTCEPSS rescore
  12. 2026-08-31 04:31 UTCEG score recompute
  13. 2026-08-30 19:17 UTCEPSS rescore
  14. 2026-08-30 03:34 UTCEG score recompute
  15. 2026-08-30 01:22 UTCEPSS rescore
  16. 2026-08-28 21:41 UTCEPSS rescore
  17. 2026-08-27 14:25 UTCEPSS rescore
  18. 2026-08-27 13:45 UTCEG score recompute
  19. 2026-08-26 14:46 UTCEPSS rescore
  20. 2026-08-26 12:44 UTCEG score recompute
  21. 2026-08-25 13:49 UTCEPSS rescore
  22. 2026-08-25 11:49 UTCEG score recompute
  23. 2026-08-24 10:57 UTCEG score recompute
  24. 2026-08-23 10:08 UTCEG score recompute
  25. 2026-08-23 00:19 UTCEPSS rescore
Show 62 more
  1. 2026-08-22 09:18 UTCEG score recompute
  2. 2026-08-21 23:49 UTCEPSS rescore
  3. 2026-08-21 08:29 UTCEG score recompute
  4. 2026-08-20 22:55 UTCEPSS rescore
  5. 2026-08-20 07:40 UTCEG score recompute
  6. 2026-08-19 17:04 UTCEPSS rescore
  7. 2026-08-19 06:51 UTCEG score recompute
  8. 2026-08-18 13:48 UTCEPSS rescore
  9. 2026-08-18 05:56 UTCEG score recompute
  10. 2026-08-17 13:47 UTCEPSS rescore
  11. 2026-08-17 04:46 UTCEG score recompute
  12. 2026-08-16 14:56 UTCEPSS rescore
  13. 2026-08-16 03:57 UTCEG score recompute
  14. 2026-08-16 02:14 UTCEPSS rescore
  15. 2026-08-15 03:09 UTCEG score recompute
  16. 2026-08-15 01:30 UTCEPSS rescore
  17. 2026-08-14 02:20 UTCEG score recompute
  18. 2026-08-13 22:00 UTCEPSS rescore
  19. 2026-08-13 01:31 UTCEG score recompute
  20. 2026-08-12 13:51 UTCEPSS rescore
  21. 2026-08-12 00:43 UTCEG score recompute
  22. 2026-08-11 00:00 UTCEPSS rescore
  23. 2026-08-09 23:06 UTCEG score recompute
  24. 2026-08-09 13:46 UTCEPSS rescore
  25. 2026-08-08 22:18 UTCEG score recompute
  26. 2026-08-08 16:37 UTCEPSS rescore
  27. 2026-08-06 20:41 UTCEG score recompute
  28. 2026-08-06 13:47 UTCEPSS rescore
  29. 2026-08-05 19:53 UTCEG score recompute
  30. 2026-08-05 19:17 UTCEPSS rescore
  31. 2026-08-04 19:04 UTCEG score recompute
  32. 2026-08-04 15:10 UTCEPSS rescore
  33. 2026-08-04 10:39 UTCEPSS rescore
  34. 2026-08-03 18:15 UTCEG score recompute
  35. 2026-08-03 10:36 UTCEPSS rescore
  36. 2026-08-02 17:14 UTCEG score recompute
  37. 2026-08-02 02:27 UTCEPSS rescore
  38. 2026-08-01 16:25 UTCEG score recompute
  39. 2026-08-01 04:16 UTCEPSS rescore
  40. 2026-07-31 15:36 UTCEG score recompute
  41. 2026-07-30 16:28 UTCEPSS rescore
  42. 2026-07-30 14:44 UTCEG score recompute
  43. 2026-07-30 01:30 UTCEPSS rescore
  44. 2026-07-29 13:55 UTCEG score recompute
  45. 2026-07-28 15:37 UTCEPSS rescore
  46. 2026-07-28 13:06 UTCEG score recompute
  47. 2026-07-27 12:14 UTCEG score recompute
  48. 2026-07-26 14:54 UTCEPSS rescore
  49. 2026-07-26 11:25 UTCEG score recompute
  50. 2026-07-25 14:18 UTCEPSS rescore
  51. 2026-07-24 14:18 UTCEPSS rescore
  52. 2026-07-23 14:18 UTCEPSS rescore
  53. 2026-07-23 03:20 UTCEG score recompute
  54. 2026-07-22 14:08 UTCEPSS rescore
  55. 2026-07-21 15:25 UTCEPSS rescore
  56. 2026-07-20 17:08 UTCEPSS rescore
  57. 2026-07-19 14:31 UTCEPSS rescore
  58. 2026-07-19 14:31 UTCEPSS rescore
  59. 2026-07-19 02:29 UTCEPSS rescore
  60. 2026-07-18 10:04 UTCEPSS rescore
  61. 2026-07-16 16:30 UTCEG score recompute
  62. 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 0% probability of exploitation in the next 30 days, which ranks it in the top 90.9% of all scored CVEs.
What is the CVSS score of CVE-2026-55406?
CVE-2026-55406 has a CVSS v3 base score of 5.9 (NVD).
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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