CVE-2026-93599

HIGHPre-NVD 7.57.5
EchelonGraph scoreMEDIUM confidence

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

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-18. A secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — Patch released this weekElevated

Also known asEUVD-2026-82894 (ENISA EUVD) · GHSA-g42g-9vm4-7gfj (GitHub Security Advisories)Source: ENISA EUVD

7.5EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 7.5Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

rustls-webpki through 0.103.12 (and 0.104.0-alpha releases before 0.104.0-alpha.7) contains a reachable panic in bit_string_flags() in src/der.rs. The input guard fails to reject a named-bit BIT STRING whose content is exactly [0x00] (zero padding bits and no data bytes), so raw_bits.len() - 1 underflows on the empty slice and the subsequent index operation panics (subtract-with-overflow in debug, index-out-of-bounds in release). The condition is reachable through the public API BorrowedCertRevocationList::from_der() when a CRL contains an issuingDistributionPoint extension with such an onlySomeReasons value. Exploitation requires an application that explicitly opts in to CRL revocation checking by passing RevocationOptions to verify_for_usage() and that parses CRL bytes obtained from a source the attacker can influence; the default rustls configuration, which does not use RevocationOptions, is unaffected. A crafted CRL causes a denial of service via the panic. Fixed in 0.103.13 and 0.104.0-alpha.7.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
65
EG Risk 65/100

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.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (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 available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.3%
EPSS %ILE
28th
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
0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-30). 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 low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.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 low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (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)14 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (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

September 18, 2026

Last Modified

September 22, 2026

Advisory Details (2)

Auto-updated Sep 18, 2026
Patch available. Sources: github.
Web page

rustls-webpki before 0.103.13 Panic via empty BIT STRING | Advisories | VulnCheck

https://www.vulncheck.com/advisories/rustls-webpki-before-0.103.13-panic-via-empty-bit-string
GitHub advisoryMentions a patch (unverified)

Panic in `BorrowedCertRevocationList::from_der` via empty `BIT STRING` in `IssuingDistributionPoint` · Advisory · rustls/webpki · GitHub

https://github.com/rustls/webpki/security/advisories/GHSA-82j2-j2ch-gfr8

Patch Availability(21)

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(3 across 3 ecosystems)
crates.io(1)
PackageVulnerable rangeFix by version rangeDependents
rustls-webpki—
  • every version up to 0.103.13: fixed in 0.103.13
  • 0.104.0-alpha.1 up to 0.104.0-alpha.7: fixed in 0.104.0-alpha.7
  • 0.0.0-0 up to 0.103.13: fixed in 0.103.13
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
rust-rustls-webpki0.102.8-5 ... 0.103.9+ds-2 (11 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
rust-rustls-webpki0.102.8-5 ... 0.103.9+ds-2 (9 versions)
  • every version up to 0.103.13+ds-1: fixed in 0.103.13+ds-1
—

Weakness Classification(1)

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

Additional Vendor Advisories

(3)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 10× in last 7d / 90× 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 166 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 66 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:36 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  3. 2026-10-31 07:15 UTCEG score recompute
  4. 2026-10-31 07:15 UTCVendor advisory
  5. 2026-10-31 07:15 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  6. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  7. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  8. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  9. 2026-10-27 16:33 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  10. 2026-10-26 16:33 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  11. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  12. 2026-10-25 13:49 UTCEG score recompute
  13. 2026-10-24 23:22 UTCEG score recompute
  14. 2026-10-24 23:22 UTCVendor advisory
  15. 2026-10-24 23:22 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  16. 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  17. 2026-10-23 16:33 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  18. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  19. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  20. 2026-10-20 16:34 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  21. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  22. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  23. 2026-10-18 15:35 UTCEG score recompute
  24. 2026-10-18 15:35 UTCVendor advisory
  25. 2026-10-18 15:35 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
Show 75 more
  1. 2026-10-18 02:58 UTCEG score recompute
  2. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  3. 2026-10-16 16:45 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  4. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  5. 2026-10-14 16:34 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  6. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  7. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  8. 2026-10-12 16:00 UTCEG score recompute
  9. 2026-10-12 16:00 UTCVendor advisory
  10. 2026-10-12 15:59 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  11. 2026-10-12 14:42 UTCEG score recompute
  12. 2026-10-11 22:30 UTCVendor advisory
  13. 2026-10-11 22:30 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  14. 2026-10-11 19:12 UTCEG score recompute
  15. 2026-10-11 16:28 UTCEG score recompute
  16. 2026-10-11 13:50 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  17. 2026-10-11 13:41 UTCEG score recompute
  18. 2026-10-11 10:15 UTCVendor advisory
  19. 2026-10-11 10:15 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  20. 2026-10-10 21:58 UTCEG score recompute
  21. 2026-10-10 21:58 UTCVendor advisory
  22. 2026-10-10 21:58 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  23. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  24. 2026-10-10 09:01 UTCVendor advisory
  25. 2026-10-10 09:01 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  26. 2026-10-09 20:46 UTCEG score recompute
  27. 2026-10-09 20:46 UTCVendor advisory
  28. 2026-10-09 20:45 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  29. 2026-10-09 20:08 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  30. 2026-10-09 08:31 UTCVendor advisory
  31. 2026-10-09 08:31 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  32. 2026-10-08 20:15 UTCEG score recompute
  33. 2026-10-08 20:15 UTCVendor advisory
  34. 2026-10-08 20:14 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  35. 2026-10-08 17:14 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  36. 2026-10-08 06:18 UTCEG score recompute
  37. 2026-10-08 06:18 UTCVendor advisory
  38. 2026-10-08 06:18 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  39. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  40. 2026-10-07 18:03 UTCVendor advisory
  41. 2026-10-07 18:03 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  42. 2026-10-07 04:49 UTCVendor advisory
  43. 2026-10-07 04:49 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  44. 2026-10-06 16:34 UTCEG score recompute
  45. 2026-10-06 16:34 UTCVendor advisory
  46. 2026-10-06 16:34 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  47. 2026-10-06 15:19 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  48. 2026-10-06 04:16 UTCEG score recompute
  49. 2026-10-06 04:16 UTCVendor advisory
  50. 2026-10-06 04:16 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  51. 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  52. 2026-10-05 16:00 UTCVendor advisory
  53. 2026-10-05 16:00 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  54. 2026-10-05 03:34 UTCEG score recompute
  55. 2026-10-05 03:34 UTCVendor advisory
  56. 2026-10-05 03:34 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  57. 2026-10-04 23:23 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  58. 2026-10-04 15:19 UTCVendor advisory
  59. 2026-10-04 15:19 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  60. 2026-10-04 02:58 UTCVendor advisory
  61. 2026-10-04 02:58 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  62. 2026-10-03 14:43 UTCEG score recompute
  63. 2026-10-03 14:43 UTCVendor advisory
  64. 2026-10-03 14:43 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  65. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  66. 2026-10-03 02:25 UTCEG score recompute
  67. 2026-10-03 02:25 UTCVendor advisory
  68. 2026-10-03 02:25 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  69. 2026-10-02 14:08 UTCVendor advisory
  70. 2026-10-02 14:08 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  71. 2026-10-02 01:52 UTCEG score recompute
  72. 2026-10-02 01:52 UTCVendor advisory
  73. 2026-10-02 01:52 UTCGHSA enrichmentGHSA-g42g-9vm4-7gfj · GitHub severity HIGH · GitHub CVSS 7.5
  74. 2026-10-01 19:51 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  75. 2026-10-01 13:38 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-93599?
CVE-2026-93599 is a high-severity vulnerability; its CVE record was published on September 18, 2026. rustls-webpki through 0.103.12 (and 0.104.0-alpha releases before 0.104.0-alpha.7) contains a reachable panic in bit_string_flags() in src/der.rs. The input guard fails to reject a named-bit BIT STRING whose content is exactly [0x00] (zero padding bits and no data bytes), so raw_bits.len() - 1…
When was CVE-2026-93599 made public?
CVE-2026-93599 was made public on April 21, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on September 18, 2026. EchelonGraph's copy of the record carries a last-modified date of September 22, 2026; the record at its source may have been updated since.
Is CVE-2026-93599 actively exploited?
CVE-2026-93599 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (28th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-93599?
CVE-2026-93599 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-93599?
A fix for CVE-2026-93599 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-93599 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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