CVE-2026-86137

MEDIUMNVD 6.16.1
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 6.1 under NVD CVSS v3. EPSS exploit probability: 0.2% (9th percentile of EPSS-scored CVEs). GitHub Security Advisory CVSS 2.9 is lower than this score; a lower GitHub score revises it only when its advisory is newer than the CVE record's last change, and this advisory (published 2026-09-05) is not newer than that change (2026-09-15), so it does not.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3

Also known asEUVD-2026-71830 (ENISA EUVD) · GHSA-cq7w-3xjv-g47g (GitHub Security Advisories)Source: ENISA EUVD

6.1EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 6.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

In libxml2 before 2.15.4, xmlFAParsePosCharGroup has an out-of-bounds read, aka an out-of-bounds read in the NXT macro in xmlregexp.

CVSS v3
6.1
EG Score
6.1MEDIUMmedium confidence
EG Risk
28
EG Risk 28/100

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)
Severity61% × 45%
Impact severity (EG Severity): CVSS 6.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 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 available. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
9th
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 (6.1): severity, escalated by confirmed exploitation. This CVE's 6.1 is its impact severity (EG Severity), not escalated.

EG Severity
6.1 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). 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.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 available. Apply it within your standard update timelines.

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.

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

September 5, 2026

Last Modified

September 15, 2026

Advisory Details (3)

Auto-updated Sep 15, 2026
Patch available. Sources: github_commit.
Web page

Out-of-bounds read in xmlFAParsePosCharGroup (#1099) · Issues · GNOME / libxml2 · GitLab

https://gitlab.gnome.org/GNOME/libxml2/-/work_items/1099
Web page

Comparing v2.15.3...v2.15.4 · GNOME/libxml2 · GitHub

https://github.com/GNOME/libxml2/compare/v2.15.3...v2.15.4
GitHub commit

commit 76fe08d97de8 (GNOME/libxml2)

Fix landed in GNOME/libxml2 commit 76fe08d97de8 — awaiting tagged release

https://github.com/GNOME/libxml2/commit/76fe08d97de88bfaef2f7d5cd27f11954cc5bee2

Vendor Advisories for CVE-2026-86137(3)

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

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatlibxml2-main-2.15.4-0.1.hum12026-09-06redhat

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)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
libxml22.12.3+dfsg-0exp1 ... 2.9.14+dfsg-1.3~deb12u6 (49 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
libxml22.12.7+dfsg+really2.9.14-2.1 ... 2.15.4+dfsg-1 (31 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
libxml22.12.7+dfsg+really2.9.14-2.1 ... 2.15.3+dfsg-1 (27 versions)
  • every version up to 2.15.4+dfsg-1: fixed in 2.15.4+dfsg-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 59× 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 156 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 56 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  3. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  4. 2026-10-29 23:55 UTCOSV refresh
  5. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  6. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  7. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  8. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  9. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  10. 2026-10-25 13:55 UTCEG score recompute
  11. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  12. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  13. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  14. 2026-10-22 12:47 UTCEG score recompute
  15. 2026-10-22 12:47 UTCVendor advisory
  16. 2026-10-22 12:47 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9
  17. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  18. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  19. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  20. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  21. 2026-10-18 03:05 UTCEG score recompute
  22. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  23. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  24. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  25. 2026-10-14 16:34 UTCEPSS rescoreEPSS 0.2% · 8th percentile
Show 75 more
  1. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  2. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  3. 2026-10-12 14:51 UTCEG score recompute
  4. 2026-10-11 19:17 UTCEG score recompute
  5. 2026-10-11 16:34 UTCEG score recompute
  6. 2026-10-11 13:51 UTCEG score recompute
  7. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  9. 2026-10-09 23:04 UTCEG score recompute
  10. 2026-10-09 23:04 UTCVendor advisory
  11. 2026-10-09 23:04 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9
  12. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  13. 2026-10-09 01:06 UTCEG score recompute
  14. 2026-10-09 01:06 UTCVendor advisory
  15. 2026-10-09 01:06 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9
  16. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  17. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  18. 2026-10-07 22:59 UTCEG score recompute
  19. 2026-10-07 22:59 UTCVendor advisory
  20. 2026-10-07 22:59 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9
  21. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  22. 2026-10-06 14:42 UTCEG score recompute
  23. 2026-10-06 14:42 UTCVendor advisory
  24. 2026-10-06 14:42 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9
  25. 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  26. 2026-10-05 16:38 UTCEG score recompute
  27. 2026-10-05 16:38 UTCVendor advisory
  28. 2026-10-05 16:38 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9
  29. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  30. 2026-10-04 18:06 UTCVendor advisory
  31. 2026-10-04 18:06 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9
  32. 2026-10-03 19:14 UTCEG score recompute
  33. 2026-10-03 19:14 UTCVendor advisory
  34. 2026-10-03 19:14 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9
  35. 2026-10-02 20:53 UTCEG score recompute
  36. 2026-10-02 20:53 UTCVendor advisory
  37. 2026-10-02 20:53 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9
  38. 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  39. 2026-10-01 22:47 UTCEG score recompute
  40. 2026-10-01 22:47 UTCVendor advisory
  41. 2026-10-01 22:47 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9
  42. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  43. 2026-10-01 00:53 UTCEG score recompute
  44. 2026-10-01 00:53 UTCVendor advisory
  45. 2026-10-01 00:53 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9
  46. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  47. 2026-09-30 02:38 UTCEG score recompute
  48. 2026-09-30 02:38 UTCVendor advisory
  49. 2026-09-30 02:38 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9
  50. 2026-09-28 20:37 UTCEG score recompute
  51. 2026-09-28 20:37 UTCVendor advisory
  52. 2026-09-28 20:37 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9
  53. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  54. 2026-09-27 22:01 UTCEG score recompute
  55. 2026-09-27 22:01 UTCVendor advisory
  56. 2026-09-27 22:01 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9
  57. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  58. 2026-09-26 23:55 UTCEG score recompute
  59. 2026-09-26 23:55 UTCVendor advisory
  60. 2026-09-26 23:55 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9
  61. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  62. 2026-09-26 01:45 UTCEG score recompute
  63. 2026-09-26 01:45 UTCVendor advisory
  64. 2026-09-26 01:44 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9
  65. 2026-09-25 00:08 UTCEG score recompute
  66. 2026-09-25 00:08 UTCVendor advisory
  67. 2026-09-25 00:08 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9
  68. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  69. 2026-09-24 01:44 UTCEG score recompute
  70. 2026-09-24 01:44 UTCVendor advisory
  71. 2026-09-24 01:44 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9
  72. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  73. 2026-09-23 03:50 UTCEG score recompute
  74. 2026-09-23 03:50 UTCVendor advisory
  75. 2026-09-23 03:50 UTCGHSA enrichmentGHSA-cq7w-3xjv-g47g · GitHub severity LOW · GitHub CVSS 2.9

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-86137?
CVE-2026-86137 is a medium-severity vulnerability; its CVE record was published on September 5, 2026. In libxml2 before 2.15.4, xmlFAParsePosCharGroup has an out-of-bounds read, aka an out-of-bounds read in the NXT macro in xmlregexp.
When was the CVE record for CVE-2026-86137 published?
The CVE record for CVE-2026-86137 was published on September 5, 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 September 15, 2026; the record at its source may have been updated since.
Is CVE-2026-86137 actively exploited?
CVE-2026-86137 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (9th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-86137?
CVE-2026-86137 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2026-86137?
A fix for CVE-2026-86137 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-86137 are linked in the Vendor Advisories panel on this page.

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