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
7.5EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is referenced (a reference tagged "Patch", often a source commit), but no release containing it is confirmed — find the release that contains it; until it is applied, mitigate (WAF / firewall / segmentation).

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
7.5HIGHmedium confidence
EG Risk
38
EG Risk 38/100

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%
EPSS PROB
0.4%
EPSS %ILE
36th
KEV
Not listed

Published

June 25, 2026

Last Modified

June 26, 2026

Advisory Details (2)

Auto-updated Jun 26, 2026
Fix referenced — no release confirmed yet. Sources: github_pr.
genericMentions a patch (unverified)

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 rangeFix by version rangeDependents
wolfssl4.6.0+p1-0+deb11u1 ... 5.9.2-1 (40 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
wolfssl5.5.4-2 ... 5.9.2-1 (27 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
wolfssl5.7.2-0.1 ... 5.9.2-1 (14 versions)
  • every version on: no fix on record
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 34× 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 247 total refreshes for this CVE.

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

Related CVEs(same product + same CWE)

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 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 0.4% probability of exploitation in the next 30 days (36th percentile of EPSS-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?
A fix for CVE-2026-55958 is referenced (a reference tagged "Patch", often a source commit), but EchelonGraph has no release containing it on record. Check that reference and the vendor's advisory for a release that contains the fix and update to it; until then, restrict network exposure of the affected system or apply the vendor's mitigation. The vendor advisories EchelonGraph has for CVE-2026-55958 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-55958

Explore →

Is Your Infrastructure Affected by CVE-2026-55958?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs