CVE-2026-9499

MEDIUMPre-NVD 6.36.3
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 6.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3% (22nd percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Trending — 4 sources updated this week

Also known asEUVD-2026-46257 (ENISA EUVD) · GHSA-8cm2-5hwv-mhv9 (GitHub Security Advisories)Source: ENISA EUVD

6.3EG
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: 0.3%CVSS: 6.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Fixed versions, as the CVE record's CNA (TQtC) states them: "Update to Qt 6.8.8, Qt 6.11.1, Qt 6.12.0, or later, or apply the referenced patch."

An out-of-bounds read (buffer over-read) vulnerability exists in QTextCodec::codecForName() in Qt. When the function is called with a QByteArray that is not NUL-terminated (for example, one created with QByteArray::fromRawData()), the codec-name matching routine reads past the end of the supplied buffer. In most cases this results in an incorrect text codec being selected; in the worst case, if the over-read reaches unmapped memory, the process crashes (denial of service). The over-read is bounded by the length of the longest codec-name candidate, and the out-of-bounds bytes are only compared internally against Qt's fixed list of codec names, so no data is disclosed to an attacker. Applications that do not pass non-NUL-terminated QByteArrays to QTextCodec::codecForName() are not exposed. The affected code resides in the Qt5Compat module from Qt 6.0.0 onward, and in Qt Core (qtbase) in Qt 4.x and Qt 5.x.

CVSS v3
6.3
EG Score
6.3MEDIUMmedium 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)
Severity63% × 45%
Impact severity (EG Severity): CVSS 6.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.3% × 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
0.3%
EPSS %ILE
22nd
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 (6.3): severity, escalated by confirmed exploitation. This CVE's 6.3 is its impact severity (EG Severity), not escalated.

EG Severity
6.3 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.3% 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: 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.

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

July 21, 2026

Last Modified

July 23, 2026

Advisory Details (4)

Auto-updated Jul 21, 2026
Patch available.
Web page
https://codereview.qt-project.org/c/qt/tqtc-qt5compat/+/725112
Web page
https://codereview.qt-project.org/c/qt/qt5compat/+/724995
Web page
https://codereview.qt-project.org/c/qt/qt5compat/+/724348
Web page
https://codereview.qt-project.org/c/qt/qt5compat/+/723911

Vendor Advisories for CVE-2026-9499(9)

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

Patch Availability(12)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatqt-1:4.8.7-10.el7_92026-10-01redhat
redhatqt5-qtbase-0:5.15.3-2.el8_8.12026-09-28redhat
redhatqt6-qt5compat-0:6.8.1-1.el10_0.12026-09-28redhat
redhatqt5-qtbase-0:5.12.5-9.el8_4.12026-09-28redhat
redhatqt5-qtbase-0:5.15.2-5.el8_6.12026-09-28redhat
redhatqt5-qtbase-0:5.15.3-2.el9_2.12026-09-23redhat
redhatqt5-qtbase-0:5.15.9-11.el9_6.12026-09-23redhat
redhatqt5-qtbase-0:5.15.9-11.el9_4.12026-09-23redhat
redhatqt6-qt5compat-0:6.10.1-1.el10_2.12026-09-09redhat
redhatqt5-qtbase-0:5.15.9-11.el9_8.12026-09-09redhat
redhatqt5-qtbase-0:5.15.3-9.el8_102026-09-09redhat
redhatqt6-main-6.11.1-2.hum12026-07-18redhat

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

(7 across 4 ecosystems)
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
qt6-5compat6.10.2-1 ... 6.9.2-3 (25 versions)
  • every version on: no fix on record
—
qtbase-opensource-src5.15.10+dfsg-1 ... 5.15.9+dfsg-3 (50 versions)
  • every version on: no fix on record
—
Debian:13(2)
PackageVulnerable rangeFix by version rangeDependents
qt6-5compat6.10.2-1 ... 6.9.2-3 (12 versions)
  • every version on: no fix on record
—
qtbase-opensource-src5.15.15+dfsg-6 ... 5.15.19+dfsg-5 (19 versions)
  • every version on: no fix on record
—
Debian:14(2)
PackageVulnerable rangeFix by version rangeDependents
qt6-5compat6.10.2-1 ... 6.9.2-3 (9 versions)
  • every version up to 6.10.2-4: fixed in 6.10.2-4
—
qtbase-opensource-src5.15.15+dfsg-6 ... 5.15.19+dfsg-3 (16 versions)
  • every version up to 5.15.19+dfsg-4: fixed in 5.15.19+dfsg-4
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
qtbase-opensource-src5.15.10+dfsg-1 ... 5.15.9+dfsg-3 (84 versions)
  • every version on: no fix on record
—

Weakness Classification(1)

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

Additional Vendor Advisories

(4)

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 11× in last 7d / 48× 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 99 of 234 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. 1 repeat row among the latest 100 is merged into the row it repeats. The 135 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-27 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  2. 2026-10-26 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  3. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  4. 2026-10-25 13:49 UTCEG score recompute
  5. 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  6. 2026-10-23 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  7. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  8. 2026-10-22 12:26 UTCEG score recompute
  9. 2026-10-22 12:26 UTCVendor advisory
  10. 2026-10-22 12:26 UTCGHSA enrichmentGHSA-8cm2-5hwv-mhv9
  11. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  12. 2026-10-20 16:34 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  13. 2026-10-19 16:34 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  14. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  15. 2026-10-18 02:58 UTCEG score recompute
  16. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  17. 2026-10-16 16:45 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  18. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  19. 2026-10-14 16:34 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  20. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  21. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  22. 2026-10-12 14:41 UTCEG score recompute
  23. 2026-10-11 19:11 UTCEG score recompute
  24. 2026-10-11 16:27 UTCEG score recompute
  25. 2026-10-11 13:50 UTCEPSS rescoreEPSS 0.3% · 21st percentile
Show 74 more
  1. 2026-10-11 13:40 UTCEG score recompute
  2. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  3. 2026-10-09 20:08 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  4. 2026-10-08 17:14 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  5. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  6. 2026-10-06 15:19 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  7. 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  8. 2026-10-04 23:23 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  9. 2026-10-04 14:50 UTCEG score recompute
  10. 2026-10-04 14:50 UTCVendor advisory
  11. 2026-10-04 14:50 UTCGHSA enrichmentGHSA-8cm2-5hwv-mhv9
  12. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  13. 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  14. 2026-10-01 19:51 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  15. 2026-10-01 07:30 UTCEG score recompute
  16. 2026-10-01 07:30 UTCVendor advisory
  17. 2026-10-01 07:30 UTCGHSA enrichmentGHSA-8cm2-5hwv-mhv9
  18. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  19. 2026-09-29 15:24 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  20. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  21. 2026-09-28 06:11 UTCEG score recompute
  22. 2026-09-28 06:11 UTCVendor advisory
  23. 2026-09-28 06:11 UTCGHSA enrichmentGHSA-8cm2-5hwv-mhv9
  24. 2026-09-27 13:49 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  25. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  26. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  27. 2026-09-24 03:24 UTCEG score recompute
  28. 2026-09-24 03:24 UTCVendor advisory
  29. 2026-09-24 03:24 UTCGHSA enrichmentGHSA-8cm2-5hwv-mhv9
  30. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  31. 2026-09-23 01:27 UTCEG score recompute
  32. 2026-09-23 01:27 UTCVendor advisory
  33. 2026-09-23 01:27 UTCGHSA enrichmentGHSA-8cm2-5hwv-mhv9
  34. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  35. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  36. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  37. 2026-09-20 05:59 UTCEG score recompute
  38. 2026-09-20 05:59 UTCVendor advisory
  39. 2026-09-20 05:59 UTCGHSA enrichmentGHSA-8cm2-5hwv-mhv9
  40. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  41. 2026-09-18 03:51 UTCEG score recompute
  42. 2026-09-18 03:51 UTCVendor advisory
  43. 2026-09-18 03:51 UTCGHSA enrichmentGHSA-8cm2-5hwv-mhv9
  44. 2026-09-17 19:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  45. 2026-09-16 14:09 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  46. 2026-09-16 12:40 UTCEG score recompute
  47. 2026-09-16 12:40 UTCVendor advisory
  48. 2026-09-16 12:40 UTCGHSA enrichmentGHSA-8cm2-5hwv-mhv9
  49. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  50. 2026-09-15 03:12 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  51. 2026-09-14 06:51 UTCEG score recompute
  52. 2026-09-14 06:51 UTCVendor advisory
  53. 2026-09-14 06:51 UTCGHSA enrichmentGHSA-8cm2-5hwv-mhv9
  54. 2026-09-13 16:48 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  55. 2026-09-13 08:19 UTCEG score recompute
  56. 2026-09-13 08:19 UTCVendor advisory
  57. 2026-09-13 08:19 UTCGHSA enrichmentGHSA-8cm2-5hwv-mhv9
  58. 2026-09-12 15:02 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  59. 2026-09-12 09:48 UTCEG score recompute
  60. 2026-09-12 09:48 UTCVendor advisory
  61. 2026-09-12 09:48 UTCGHSA enrichmentGHSA-8cm2-5hwv-mhv9
  62. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  63. 2026-09-11 09:38 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  64. 2026-09-11 09:06 UTCEG score recompute
  65. 2026-09-11 09:06 UTCVendor advisory
  66. 2026-09-11 09:06 UTCGHSA enrichmentGHSA-8cm2-5hwv-mhv9
  67. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  68. 2026-09-09 11:34 UTCEG score recompute
  69. 2026-09-09 11:34 UTCVendor advisory
  70. 2026-09-09 11:34 UTCGHSA enrichmentGHSA-8cm2-5hwv-mhv9
  71. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  72. 2026-09-07 22:39 UTCEG score recompute
  73. 2026-09-07 22:39 UTCVendor advisory
  74. 2026-09-07 22:39 UTCGHSA enrichmentGHSA-8cm2-5hwv-mhv9

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Frequently asked(5)

What is CVE-2026-9499?
CVE-2026-9499 is a medium-severity vulnerability; its CVE record was published on July 21, 2026. An out-of-bounds read (buffer over-read) vulnerability exists in QTextCodec::codecForName() in Qt. When the function is called with a QByteArray that is not NUL-terminated (for example, one created with QByteArray::fromRawData()), the codec-name matching routine reads past the end of the supplied…
When was the CVE record for CVE-2026-9499 published?
The CVE record for CVE-2026-9499 was published on July 21, 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 July 23, 2026; the record at its source may have been updated since.
Is CVE-2026-9499 actively exploited?
CVE-2026-9499 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (22nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-9499?
CVE-2026-9499 has a CVSS base score of 6.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-9499?
A fix for CVE-2026-9499 is available: update to the fixed version the vendor names in its advisory. Fixed versions, as the CVE record's CNA (TQtC) states them: "Update to Qt 6.8.8, Qt 6.11.1, Qt 6.12.0, or later, or apply the referenced patch." The vendor advisories EchelonGraph has for CVE-2026-9499 are linked in the Vendor Advisories panel on this page.

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