CVE-2026-16634

CRITICALPre-NVD 9.89.8
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-24. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.8Exploit: None knownExposed: 0

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

TOML::XS versions before 0.06 for Perl bundle an unsupported and vulnerable version of tomlc99.

The tomlc99 library is no longer maintained, and has an uncontrolled recursion vulnerability publicly reported in the issue tracker.

Any caller that passes untrusted TOML to from_toml risks a stack overflow from a deeply-nested document.

TOML::XS version 0.06 or later uses the successor tomlc17 library.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
59(Track)
EG Risk 59/100SSVC: 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
Severity98% × 45%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
43%
KEV
Not listed

Published

July 24, 2026

Last Modified

July 27, 2026

Advisory Details (6)

Auto-updated Sep 14, 2026
No patch confirmed yet.
generic

Stack Overflow via Uncontrolled Recursion in parse_keyval and parse_array · Issue #97 · cktan/tomlc99 · GitHub

https://github.com/cktan/tomlc99/issues/97
generic

oss-security - CVE-2026-16634: TOML::XS versions before 0.06 for Perl bundle an unsupported and vulnerable version of tomlc99

http://www.openwall.com/lists/oss-security/2026/07/24/4
generic

TOML: English v1.0.0

https://toml.io/en/v1.0.0
generic

GitHub - cktan/tomlc17: Lightweight, strictly compliant TOML v1.1 parser for C and C++. · GitHub

https://github.com/cktan/tomlc17

Vendor Advisories for CVE-2026-16634(1)

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

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 35× in last 7d / 155× 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 367 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-16634?
CVE-2026-16634 is a critical vulnerability published on July 24, 2026. TOML::XS versions before 0.06 for Perl bundle an unsupported and vulnerable version of tomlc99. The tomlc99 library is no longer maintained, and has an uncontrolled recursion vulnerability publicly reported in the issue tracker. Any caller that passes untrusted TOML to from_toml risks a stack…
When was CVE-2026-16634 disclosed?
CVE-2026-16634 was first published in the National Vulnerability Database on July 24, 2026, with the most recent update on July 27, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-16634 actively exploited?
CVE-2026-16634 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 57.4% of all scored CVEs.
What is the CVSS score of CVE-2026-16634?
CVE-2026-16634 has a CVSS v3.1 base score of 9.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-16634?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-16634, 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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