CVE-2026-76781

MEDIUMPre-NVD 5.55.5
EchelonGraph scoreMEDIUM confidence

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

Score 5.5 from GitHub Security Advisory published 2026-09-17. A secondary CVSS source baseline 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 5 sources updated this week

Also known asEUVD-2026-81679 (ENISA EUVD) · GHSA-2j5r-8qjf-mq34 (GitHub Security Advisories)Source: ENISA EUVD

5.5EG
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: 5.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

A flaw was found in libxml2. A local user or an attacker providing a specially crafted XML catalog can trigger a NULL pointer dereference during XML catalog parsing. This occurs when a nextCatalog element lacks its mandatory catalog attribute, leading to the application crashing and causing a Denial of Service (DoS).

CVSS v3
5.5
EG Score
5.5MEDIUMmedium confidence
EG Risk
25
EG Risk 25/100

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)
Severity55% × 45%
Impact severity (EG Severity): CVSS 5.5 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
4th
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 (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.

EG Severity
5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS. 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 17, 2026

Last Modified

October 30, 2026

Advisory Details (4)

Auto-updated Sep 17, 2026
Patch available. Sources: redhat.
Web page

catalog: Fix NULL deref for nextCatalog without 'catalog' attribute (!442) · Merge requests · GNOME / libxml2 · GitLab

https://gitlab.gnome.org/GNOME/libxml2/-/merge_requests/442
Red Hat

2519776 – (CVE-2026-76781) CVE-2026-76781 libxml2: libxml2: NULL pointer dereference parsing nextCatalog without catalog attribute

https://bugzilla.redhat.com/show_bug.cgi?id=2519776
Red HatMentions a patch (unverified)

CVE-2026-76781 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-76781

Vendor Advisories for CVE-2026-76781(2)

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

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntupython3-libxml2 (2.9.10+dfsg-5ubuntu0.20.04.10+esm6) @ focal2026-10-30ubuntu
redhatlibxml2-main-2.15.3-0.1.3.hum12026-08-20redhat

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.

Additional Vendor Advisories

(1)

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 14× in last 7d / 68× 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 144 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 44 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 16:46 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  2. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  3. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  4. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  5. 2026-10-30 07:26 UTCEG score recompute
  6. 2026-10-30 07:26 UTCVendor advisory
  7. 2026-10-30 07:26 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  8. 2026-10-30 06:30 UTCEG score recompute
  9. 2026-10-30 06:30 UTCVendor advisory
  10. 2026-10-30 06:30 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  11. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  12. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  13. 2026-10-28 03:25 UTCOSV refresh
  14. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  15. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  16. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  17. 2026-10-25 14:01 UTCEG score recompute
  18. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  19. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  20. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  21. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  22. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  23. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  24. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  25. 2026-10-18 03:12 UTCEG score recompute
Show 75 more
  1. 2026-10-17 18:37 UTCEG score recompute
  2. 2026-10-17 18:37 UTCVendor advisory
  3. 2026-10-17 18:36 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  4. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  5. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  6. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  7. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  8. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  9. 2026-10-12 15:38 UTCEG score recompute
  10. 2026-10-11 19:23 UTCEG score recompute
  11. 2026-10-11 16:39 UTCEG score recompute
  12. 2026-10-11 14:01 UTCVendor advisory
  13. 2026-10-11 14:01 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  14. 2026-10-11 13:58 UTCEG score recompute
  15. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  16. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  17. 2026-10-10 15:15 UTCEG score recompute
  18. 2026-10-10 15:15 UTCVendor advisory
  19. 2026-10-10 15:14 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  20. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  21. 2026-10-09 16:41 UTCVendor advisory
  22. 2026-10-09 16:41 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  23. 2026-10-08 18:02 UTCEG score recompute
  24. 2026-10-08 18:02 UTCVendor advisory
  25. 2026-10-08 18:02 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  26. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  27. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  28. 2026-10-07 18:08 UTCVendor advisory
  29. 2026-10-07 18:08 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  30. 2026-10-06 17:56 UTCEG score recompute
  31. 2026-10-06 17:56 UTCVendor advisory
  32. 2026-10-06 17:56 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  33. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  34. 2026-10-05 19:23 UTCEG score recompute
  35. 2026-10-05 19:23 UTCVendor advisory
  36. 2026-10-05 19:23 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  37. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  38. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  39. 2026-10-04 20:38 UTCVendor advisory
  40. 2026-10-04 20:38 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  41. 2026-10-03 22:05 UTCEG score recompute
  42. 2026-10-03 22:05 UTCVendor advisory
  43. 2026-10-03 22:05 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  44. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  45. 2026-10-02 23:31 UTCEG score recompute
  46. 2026-10-02 23:31 UTCVendor advisory
  47. 2026-10-02 23:31 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  48. 2026-10-02 00:54 UTCEG score recompute
  49. 2026-10-02 00:54 UTCVendor advisory
  50. 2026-10-02 00:54 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  51. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  52. 2026-10-01 02:14 UTCEG score recompute
  53. 2026-10-01 02:14 UTCVendor advisory
  54. 2026-10-01 02:14 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  55. 2026-09-30 03:41 UTCEG score recompute
  56. 2026-09-30 03:41 UTCVendor advisory
  57. 2026-09-30 03:41 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  58. 2026-09-29 15:24 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  59. 2026-09-29 05:06 UTCEG score recompute
  60. 2026-09-29 05:06 UTCVendor advisory
  61. 2026-09-29 05:06 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  62. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  63. 2026-09-28 06:32 UTCEG score recompute
  64. 2026-09-28 06:32 UTCVendor advisory
  65. 2026-09-28 06:32 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  66. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  67. 2026-09-27 07:59 UTCEG score recompute
  68. 2026-09-27 07:59 UTCVendor advisory
  69. 2026-09-27 07:59 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  70. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  71. 2026-09-26 09:25 UTCEG score recompute
  72. 2026-09-26 09:25 UTCVendor advisory
  73. 2026-09-26 09:25 UTCGHSA enrichmentGHSA-2j5r-8qjf-mq34 · GitHub CVSS 5.5
  74. 2026-09-26 00:28 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  75. 2026-09-25 10:52 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-76781?
CVE-2026-76781 is a medium-severity vulnerability; its CVE record was published on September 17, 2026. A flaw was found in libxml2. A local user or an attacker providing a specially crafted XML catalog can trigger a NULL pointer dereference during XML catalog parsing. This occurs when a nextCatalog element lacks its mandatory catalog attribute, leading to the application crashing and causing a…
When was CVE-2026-76781 made public?
CVE-2026-76781 was made public on August 19, 2026: that is the date its CVE record's CNA, Red Hat, Inc., gives for when the vulnerability was made public. The CVE record itself was published on September 17, 2026. EchelonGraph's copy of the record carries a last-modified date of October 30, 2026; the record at its source may have been updated since.
Is CVE-2026-76781 actively exploited?
CVE-2026-76781 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (4th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-76781?
CVE-2026-76781 has a CVSS base score of 5.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-76781?
A fix for CVE-2026-76781 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-76781 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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