CVE-2026-55958

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-06-25. NVD baseline CVSS 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

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

Out-of-bounds write in the Renesas TSIP TLS 1.3 transcript buffer. In tsip_StoreMessage() the capacity check guarding the fixed message bag (MSGBAG_SIZE) sets an error code but fails to return, so execution falls through to an XMEMCPY that writes past the end of the buffer once the accumulated TLS 1.3 handshake transcript exceeds MSGBAG_SIZE (8 KB), corrupting adjacent heap state and potentially causing a remote denial of service crash. The bag is sized to hold a normal handshake, so this is reached only by an unusually large but valid certificate chain, or by a malicious or man-in-the-middle server sending an oversized handshake message to a client that does not strictly verify the chain. This only affects builds using the Renesas TSIP TLS port (WOLFSSL_RENESAS_TSIP_TLS) as a TLS 1.3 client on Renesas MCUs with TSIP hardware enabled, and is rated High within those builds. All other configurations are unaffected.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
38(Track)
EG Risk 38/100SSVC: 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
Severity75% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
37%
KEV
Not listed

Published

June 25, 2026

Last Modified

June 26, 2026

Advisory Details (2)

Auto-updated Jun 26, 2026
Patch available. Sources: github_pr.
generic Patch Available

wolfSSL Security Vulnerabilities | Documentation - wolfSSL

https://www.wolfssl.com/docs/security-vulnerabilities/
github_pr

Renesas TSIP: skip XMEMCPY on MEMORY_E from tsip_StoreMessage()

Fix merged in wolfSSL/wolfssl PR #10705 on 2026-06-16 — awaiting tagged release

https://github.com/wolfSSL/wolfssl/pull/10705

Vendor Advisories for CVE-2026-55958(2)

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

Affected Packages

(3 across 3 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
wolfssl4.6.0+p1-0+deb11u1 ... 5.9.2-1 (40 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
wolfssl5.5.4-2 ... 5.9.2-1 (27 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
wolfssl5.7.2-0.1 ... 5.9.2-1 (14 versions)——

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 22× in last 7d / 106× 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.

Showing the most recent 100 of 197 total refreshes for this CVE.

  1. 2026-08-25 13:49 UTCEPSS rescore
  2. 2026-08-25 01:56 UTCEG score recompute
  3. 2026-08-25 01:56 UTCGHSA enrichment
  4. 2026-08-24 13:11 UTCEG score recompute
  5. 2026-08-24 13:11 UTCGHSA enrichment
  6. 2026-08-24 00:26 UTCGHSA enrichment
  7. 2026-08-23 11:41 UTCEG score recompute
  8. 2026-08-23 11:41 UTCGHSA enrichment
  9. 2026-08-23 00:19 UTCEPSS rescore
  10. 2026-08-22 22:56 UTCGHSA enrichment
  11. 2026-08-22 10:10 UTCEG score recompute
  12. 2026-08-22 10:10 UTCGHSA enrichment
  13. 2026-08-21 23:49 UTCEPSS rescore
  14. 2026-08-21 21:17 UTCGHSA enrichment
  15. 2026-08-21 08:32 UTCEG score recompute
  16. 2026-08-21 08:32 UTCGHSA enrichment
  17. 2026-08-20 22:55 UTCEPSS rescore
  18. 2026-08-20 19:46 UTCGHSA enrichment
  19. 2026-08-20 07:01 UTCEG score recompute
  20. 2026-08-20 07:01 UTCGHSA enrichment
  21. 2026-08-19 17:04 UTCEPSS rescore
  22. 2026-08-19 14:12 UTCGHSA enrichment
  23. 2026-08-19 01:14 UTCEG score recompute
  24. 2026-08-19 01:14 UTCGHSA enrichment
  25. 2026-08-18 13:48 UTCEPSS rescore
Show 75 more
  1. 2026-08-17 13:47 UTCEPSS rescore
  2. 2026-08-17 11:49 UTCGHSA enrichment
  3. 2026-08-16 22:58 UTCEG score recompute
  4. 2026-08-16 22:58 UTCGHSA enrichment
  5. 2026-08-16 14:56 UTCEPSS rescore
  6. 2026-08-16 10:12 UTCEG score recompute
  7. 2026-08-16 10:12 UTCGHSA enrichment
  8. 2026-08-16 02:14 UTCEPSS rescore
  9. 2026-08-15 21:28 UTCGHSA enrichment
  10. 2026-08-15 08:43 UTCEG score recompute
  11. 2026-08-15 08:43 UTCGHSA enrichment
  12. 2026-08-15 01:30 UTCEPSS rescore
  13. 2026-08-14 19:58 UTCGHSA enrichment
  14. 2026-08-14 07:13 UTCEG score recompute
  15. 2026-08-14 07:13 UTCGHSA enrichment
  16. 2026-08-13 22:00 UTCEPSS rescore
  17. 2026-08-13 18:27 UTCGHSA enrichment
  18. 2026-08-13 03:35 UTCGHSA enrichment
  19. 2026-08-12 14:50 UTCEG score recompute
  20. 2026-08-12 14:50 UTCGHSA enrichment
  21. 2026-08-12 13:51 UTCEPSS rescore
  22. 2026-08-12 02:05 UTCEG score recompute
  23. 2026-08-12 02:05 UTCGHSA enrichment
  24. 2026-08-11 13:19 UTCGHSA enrichment
  25. 2026-08-11 00:34 UTCEG score recompute
  26. 2026-08-11 00:34 UTCGHSA enrichment
  27. 2026-08-11 00:00 UTCEPSS rescore
  28. 2026-08-10 11:48 UTCGHSA enrichment
  29. 2026-08-09 23:03 UTCEG score recompute
  30. 2026-08-09 23:03 UTCGHSA enrichment
  31. 2026-08-09 13:46 UTCEPSS rescore
  32. 2026-08-09 10:18 UTCGHSA enrichment
  33. 2026-08-08 21:33 UTCEG score recompute
  34. 2026-08-08 21:33 UTCGHSA enrichment
  35. 2026-08-08 16:37 UTCEPSS rescore
  36. 2026-08-08 08:47 UTCGHSA enrichment
  37. 2026-08-07 20:02 UTCEG score recompute
  38. 2026-08-07 20:02 UTCGHSA enrichment
  39. 2026-08-07 07:17 UTCGHSA enrichment
  40. 2026-08-06 18:32 UTCEG score recompute
  41. 2026-08-06 18:32 UTCGHSA enrichment
  42. 2026-08-06 13:47 UTCEPSS rescore
  43. 2026-08-06 05:47 UTCEG score recompute
  44. 2026-08-06 05:47 UTCGHSA enrichment
  45. 2026-08-05 19:17 UTCEPSS rescore
  46. 2026-08-05 17:02 UTCGHSA enrichment
  47. 2026-08-05 03:49 UTCEG score recompute
  48. 2026-08-05 03:49 UTCGHSA enrichment
  49. 2026-08-04 15:10 UTCEPSS rescore
  50. 2026-08-04 15:03 UTCEG score recompute
  51. 2026-08-04 15:03 UTCGHSA enrichment
  52. 2026-08-04 10:39 UTCEPSS rescore
  53. 2026-08-03 20:41 UTCEG score recompute
  54. 2026-08-03 20:41 UTCGHSA enrichment
  55. 2026-08-03 10:36 UTCEPSS rescore
  56. 2026-08-03 07:54 UTCGHSA enrichment
  57. 2026-08-02 19:09 UTCGHSA enrichment
  58. 2026-08-02 06:24 UTCEG score recompute
  59. 2026-08-02 06:23 UTCGHSA enrichment
  60. 2026-08-02 02:27 UTCEPSS rescore
  61. 2026-08-01 17:25 UTCGHSA enrichment
  62. 2026-08-01 04:40 UTCEG score recompute
  63. 2026-08-01 04:40 UTCGHSA enrichment
  64. 2026-08-01 04:16 UTCEPSS rescore
  65. 2026-07-31 15:48 UTCGHSA enrichment
  66. 2026-07-31 02:52 UTCEG score recompute
  67. 2026-07-31 02:52 UTCGHSA enrichment
  68. 2026-07-30 16:28 UTCEPSS rescore
  69. 2026-07-30 14:01 UTCEG score recompute
  70. 2026-07-30 14:01 UTCGHSA enrichment
  71. 2026-07-30 01:30 UTCEPSS rescore
  72. 2026-07-30 01:30 UTCEPSS rescore
  73. 2026-07-30 00:41 UTCGHSA enrichment
  74. 2026-07-29 09:49 UTCGHSA enrichment
  75. 2026-07-28 21:03 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-55958?
CVE-2026-55958 is a high vulnerability published on June 25, 2026. Out-of-bounds write in the Renesas TSIP TLS 1.3 transcript buffer. In tsipStoreMessage() the capacity check guarding the fixed message bag (MSGBAGSIZE) sets an error code but fails to return, so execution falls through to an XMEMCPY that writes past the end of the buffer once the accumulated TLS…
When was CVE-2026-55958 disclosed?
CVE-2026-55958 was first published in the National Vulnerability Database on June 25, 2026, with the most recent update on June 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55958 actively exploited?
CVE-2026-55958 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 63.2% of all scored CVEs.
What is the CVSS score of CVE-2026-55958?
CVE-2026-55958 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-55958?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55958, 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.

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