CVE-2026-55958

HIGHNVD 7.57.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

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, GitHub Security Advisory, NVD CVSS v3
Trending — 3 sources updated this week

Also known asEUVD-2026-39546 (ENISA EUVD) · GHSA-8mfx-6cpc-cr47 (GitHub Security Advisories)Source: ENISA EUVD

7.5EG
EchelonGraph verdictPlan mitigationNo release containing the referenced fix is confirmed: check the referenced fix and the vendor's advisory for a release that contains it; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule (the SSVC decision on this page).
  • 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
34
EG Risk 34/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule.
EPSS PROB
0.4%
EPSS %ILE
38th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.

EG Severity
7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-29). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

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.
Web pageMentions a patch (unverified)

wolfSSL Security Vulnerabilities | Documentation - wolfSSL

https://www.wolfssl.com/docs/security-vulnerabilities/
GitHub pull request

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 9× in last 7d / 43× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 283 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 183 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  3. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  4. 2026-10-30 12:40 UTCEG score recompute
  5. 2026-10-30 12:40 UTCGHSA enrichmentGHSA-8mfx-6cpc-cr47 · GitHub severity HIGH · GitHub CVSS 7.5
  6. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  7. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  8. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  9. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  10. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  11. 2026-10-25 14:18 UTCEG score recompute
  12. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  13. 2026-10-23 20:00 UTCEG score recompute
  14. 2026-10-23 20:00 UTCGHSA enrichmentGHSA-8mfx-6cpc-cr47 · GitHub severity HIGH · GitHub CVSS 7.5
  15. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  16. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  17. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  18. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  19. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  20. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  21. 2026-10-18 03:29 UTCEG score recompute
  22. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  23. 2026-10-17 03:12 UTCEG score recompute
  24. 2026-10-17 03:12 UTCGHSA enrichmentGHSA-8mfx-6cpc-cr47 · GitHub severity HIGH · GitHub CVSS 7.5
  25. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.4% · 37th percentile
Show 75 more
  1. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  2. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  3. 2026-10-13 22:54 UTCOSV refresh
  4. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  5. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  6. 2026-10-12 15:55 UTCEG score recompute
  7. 2026-10-11 19:38 UTCEG score recompute
  8. 2026-10-11 16:53 UTCEG score recompute
  9. 2026-10-11 14:16 UTCEG score recompute
  10. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  11. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  12. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  13. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  14. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  15. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  16. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  17. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  18. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  19. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  20. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  21. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  22. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  23. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  24. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  25. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  26. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  27. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  28. 2026-09-23 08:29 UTCEG score recompute
  29. 2026-09-23 08:29 UTCGHSA enrichmentGHSA-8mfx-6cpc-cr47 · GitHub severity HIGH · GitHub CVSS 7.5
  30. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  31. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  32. 2026-09-18 07:20 UTCEG score recompute
  33. 2026-09-18 07:20 UTCGHSA enrichmentGHSA-8mfx-6cpc-cr47 · GitHub severity HIGH · GitHub CVSS 7.5
  34. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  35. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  36. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  37. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  38. 2026-09-14 01:17 UTCEG score recompute
  39. 2026-09-14 01:17 UTCGHSA enrichmentGHSA-8mfx-6cpc-cr47 · GitHub severity HIGH · GitHub CVSS 7.5
  40. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  41. 2026-09-13 09:37 UTCGHSA enrichmentGHSA-8mfx-6cpc-cr47 · GitHub severity HIGH · GitHub CVSS 7.5
  42. 2026-09-12 15:42 UTCEG score recompute
  43. 2026-09-12 15:42 UTCGHSA enrichmentGHSA-8mfx-6cpc-cr47 · GitHub severity HIGH · GitHub CVSS 7.5
  44. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  45. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  46. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  47. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  48. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  49. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  50. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  51. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  52. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  53. 2026-08-30 19:30 UTCEG score recompute
  54. 2026-08-30 19:30 UTCGHSA enrichmentGHSA-8mfx-6cpc-cr47 · GitHub severity HIGH · GitHub CVSS 7.5
  55. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  56. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  57. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  58. 2026-08-27 23:17 UTCEG score recompute
  59. 2026-08-27 23:17 UTCGHSA enrichmentGHSA-8mfx-6cpc-cr47 · GitHub severity HIGH · GitHub CVSS 7.5
  60. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  61. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  62. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  63. 2026-08-25 01:56 UTCEG score recompute
  64. 2026-08-25 01:56 UTCGHSA enrichmentGHSA-8mfx-6cpc-cr47 · GitHub severity HIGH · GitHub CVSS 7.5
  65. 2026-08-24 13:11 UTCEG score recompute
  66. 2026-08-24 13:11 UTCGHSA enrichmentGHSA-8mfx-6cpc-cr47 · GitHub severity HIGH · GitHub CVSS 7.5
  67. 2026-08-24 00:26 UTCGHSA enrichmentGHSA-8mfx-6cpc-cr47 · GitHub severity HIGH · GitHub CVSS 7.5
  68. 2026-08-23 11:41 UTCEG score recompute
  69. 2026-08-23 11:41 UTCGHSA enrichmentGHSA-8mfx-6cpc-cr47 · GitHub severity HIGH · GitHub CVSS 7.5
  70. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  71. 2026-08-22 22:56 UTCGHSA enrichmentGHSA-8mfx-6cpc-cr47 · GitHub severity HIGH · GitHub CVSS 7.5
  72. 2026-08-22 10:10 UTCEG score recompute
  73. 2026-08-22 10:10 UTCGHSA enrichmentGHSA-8mfx-6cpc-cr47 · GitHub severity HIGH · GitHub CVSS 7.5
  74. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  75. 2026-08-21 21:17 UTCGHSA enrichmentGHSA-8mfx-6cpc-cr47 · GitHub severity HIGH · GitHub CVSS 7.5

Frequently asked(5)

What is CVE-2026-55958?
CVE-2026-55958 is a high-severity vulnerability; its CVE record was published on June 25, 2026. 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…
When was the CVE record for CVE-2026-55958 published?
The CVE record for CVE-2026-55958 was published on June 25, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of June 26, 2026; the record at its source may have been updated since.
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 (38th 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

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