CVE-2026-63883

HIGHPre-NVD 7.37.3
EchelonGraph scoreMEDIUM confidence

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

Score 7.3 from GitHub Security Advisory (severity: HIGH) published 2026-07-19. The CNA's CVSS baseline 7.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: the CNA's CVSS, EPSS, GitHub Security Advisory
Trending — 4 sources updated this week

Also known asEUVD-2026-45768 (ENISA EUVD) · GHSA-rjh6-3wfg-m2hh (GitHub Security Advisories)Source: ENISA EUVD

7.3EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 7.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

In the Linux kernel, the following vulnerability has been resolved:

serial: qcom_geni: fix kfifo underflow when flush precedes DMA completion IRQ

When uart_flush_buffer() runs before the DMA completion IRQ is delivered, the following race can occur (all steps serialized by uart_port_lock):

  • DMA starts: tx_remaining = N, kfifo contains N bytes
  • DMA completes in hardware; IRQ is pending but not yet delivered
  • uart_flush_buffer() acquires the port lock and calls kfifo_reset(),
making kfifo_len() = 0 while tx_remaining remains N
  • uart_flush_buffer() releases the port lock
  • DMA IRQ fires; handle_tx_dma() acquires the port lock and calls
uart_xmit_advance(uport, tx_remaining) on an empty kfifo

uart_xmit_advance() increments kfifo->out by tx_remaining. Since kfifo_reset() already set both in and out to 0, out wraps past in, causing kfifo_len() to return UART_XMIT_SIZE - tx_remaining. The next start_tx_dma() call then submits a DMA transfer of stale buffer data.

Fix this by snapshotting kfifo_len() at the start of handle_tx_dma() and skipping uart_xmit_advance() when fifo_len < tx_remaining, which indicates the kfifo was reset by a preceding flush.

CVSS v3
7.3
EG Score
7.3HIGHmedium confidence
EG Risk
33
EG Risk 33/100

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)
Severity73% × 45%
Impact severity (EG Severity): CVSS 7.3 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 BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from 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
6th
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 (7.3): severity, escalated by confirmed exploitation. This CVE's 7.3 is its impact severity (EG Severity), not escalated.

EG Severity
7.3 HIGHCVSS-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 (model v2026.06.15, score date 2026-10-27). 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; Track* at high (mission-essential systems).CISA BOD 26-04: 14 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 low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from 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; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” 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 19, 2026

Last Modified

August 5, 2026

Advisory Details (5)

Auto-updated Jul 21, 2026
Patch available.
Web page

serial: qcom_geni: fix kfifo underflow when flush precedes DMA completion IRQ - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c91ea13375f70f6271a0183445e34e83b8f4d8f7
Web page

serial: qcom_geni: fix kfifo underflow when flush precedes DMA completion IRQ - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b1159dce10b38eb795e4c96cdc4d34b83cec81c5
Web page

serial: qcom_geni: fix kfifo underflow when flush precedes DMA completion IRQ - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/654f45a8569f3cd6ff20bd724a18e0cce65893ba
Web page

serial: qcom_geni: fix kfifo underflow when flush precedes DMA completion IRQ - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/452d6fa37ae9b021f4f6d397dbae077f7296f6f4
Web page

serial: qcom_geni: fix kfifo underflow when flush precedes DMA completion IRQ - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0d2c41a8b00934ddf8a7c1b4cf72dffa1e629c46

Vendor Advisories for CVE-2026-63883(1)

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

Patch Availability(14)

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

(2 across 2 ecosystems)
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.38-1 ... 6.12.94-1~bpo12+1 (27 versions)
  • every version up to 6.12.94-1: fixed in 6.12.94-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.0.9-1~bpo13+1 (142 versions)
  • every version up to 7.0.12-1: fixed in 7.0.12-1
—

All Vendor Advisories

(14)

Data Freshness Timeline

(refreshed 11× in last 7d / 46× 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 310 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 210 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  2. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  3. 2026-10-27 18:33 UTCEG score recompute
  4. 2026-10-27 18:33 UTCVendor advisory
  5. 2026-10-27 18:33 UTCGHSA enrichmentGHSA-rjh6-3wfg-m2hh · GitHub severity HIGH · GitHub CVSS 7.3
  6. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  7. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  8. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  9. 2026-10-25 14:13 UTCEG score recompute
  10. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  11. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  12. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  13. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  14. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  15. 2026-10-20 09:16 UTCEG score recompute
  16. 2026-10-20 09:16 UTCGHSA enrichmentGHSA-rjh6-3wfg-m2hh · GitHub severity HIGH · GitHub CVSS 7.3
  17. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  18. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  19. 2026-10-18 03:23 UTCEG score recompute
  20. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  21. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  22. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  23. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  24. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  25. 2026-10-13 11:50 UTCEG score recompute
Show 75 more
  1. 2026-10-13 11:50 UTCGHSA enrichmentGHSA-rjh6-3wfg-m2hh · GitHub severity HIGH · GitHub CVSS 7.3
  2. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  3. 2026-10-12 15:48 UTCEG score recompute
  4. 2026-10-11 19:33 UTCEG score recompute
  5. 2026-10-11 16:48 UTCEG score recompute
  6. 2026-10-11 14:09 UTCEG score recompute
  7. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  9. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  10. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  11. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  12. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  13. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  14. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  15. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  16. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  17. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  18. 2026-10-01 08:58 UTCEG score recompute
  19. 2026-10-01 08:58 UTCVendor advisory
  20. 2026-10-01 08:58 UTCGHSA enrichmentGHSA-rjh6-3wfg-m2hh · GitHub severity HIGH · GitHub CVSS 7.3
  21. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  22. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  23. 2026-09-28 07:34 UTCEG score recompute
  24. 2026-09-28 07:34 UTCVendor advisory
  25. 2026-09-28 07:34 UTCGHSA enrichmentGHSA-rjh6-3wfg-m2hh · GitHub severity HIGH · GitHub CVSS 7.3
  26. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  27. 2026-09-24 04:15 UTCEG score recompute
  28. 2026-09-24 04:15 UTCVendor advisory
  29. 2026-09-24 04:15 UTCGHSA enrichmentGHSA-rjh6-3wfg-m2hh · GitHub severity HIGH · GitHub CVSS 7.3
  30. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  31. 2026-09-23 02:11 UTCEG score recompute
  32. 2026-09-23 02:11 UTCVendor advisory
  33. 2026-09-23 02:11 UTCGHSA enrichmentGHSA-rjh6-3wfg-m2hh · GitHub severity HIGH · GitHub CVSS 7.3
  34. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  35. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  36. 2026-09-18 04:24 UTCEG score recompute
  37. 2026-09-18 04:24 UTCVendor advisory
  38. 2026-09-18 04:24 UTCGHSA enrichmentGHSA-rjh6-3wfg-m2hh · GitHub severity HIGH · GitHub CVSS 7.3
  39. 2026-09-17 10:00 UTCEG score recompute
  40. 2026-09-17 10:00 UTCVendor advisory
  41. 2026-09-17 10:00 UTCGHSA enrichmentGHSA-rjh6-3wfg-m2hh · GitHub severity HIGH · GitHub CVSS 7.3
  42. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  43. 2026-09-16 13:08 UTCEG score recompute
  44. 2026-09-16 13:08 UTCVendor advisory
  45. 2026-09-16 13:07 UTCGHSA enrichmentGHSA-rjh6-3wfg-m2hh · GitHub severity HIGH · GitHub CVSS 7.3
  46. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  47. 2026-09-14 04:55 UTCEG score recompute
  48. 2026-09-14 04:55 UTCVendor advisory
  49. 2026-09-14 04:55 UTCGHSA enrichmentGHSA-rjh6-3wfg-m2hh · GitHub severity HIGH · GitHub CVSS 7.3
  50. 2026-09-13 16:15 UTCVendor advisory
  51. 2026-09-13 16:15 UTCGHSA enrichmentGHSA-rjh6-3wfg-m2hh · GitHub severity HIGH · GitHub CVSS 7.3
  52. 2026-09-13 03:34 UTCEG score recompute
  53. 2026-09-13 03:34 UTCVendor advisory
  54. 2026-09-13 03:34 UTCGHSA enrichmentGHSA-rjh6-3wfg-m2hh · GitHub severity HIGH · GitHub CVSS 7.3
  55. 2026-09-12 10:11 UTCVendor advisory
  56. 2026-09-12 10:11 UTCGHSA enrichmentGHSA-rjh6-3wfg-m2hh · GitHub severity HIGH · GitHub CVSS 7.3
  57. 2026-09-11 19:41 UTCEG score recompute
  58. 2026-09-11 19:41 UTCVendor advisory
  59. 2026-09-11 19:41 UTCGHSA enrichmentGHSA-rjh6-3wfg-m2hh · GitHub severity HIGH · GitHub CVSS 7.3
  60. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  61. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  62. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  63. 2026-09-07 23:38 UTCEG score recompute
  64. 2026-09-07 23:38 UTCVendor advisory
  65. 2026-09-07 23:37 UTCGHSA enrichmentGHSA-rjh6-3wfg-m2hh · GitHub severity HIGH · GitHub CVSS 7.3
  66. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  67. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  68. 2026-09-06 13:04 UTCVendor advisory
  69. 2026-09-06 13:04 UTCGHSA enrichmentGHSA-rjh6-3wfg-m2hh · GitHub severity HIGH · GitHub CVSS 7.3
  70. 2026-09-05 20:12 UTCEG score recompute
  71. 2026-09-05 20:12 UTCVendor advisory
  72. 2026-09-05 20:11 UTCGHSA enrichmentGHSA-rjh6-3wfg-m2hh · GitHub severity HIGH · GitHub CVSS 7.3
  73. 2026-09-05 15:31 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  74. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  75. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.2% · 6th percentile

Frequently asked(5)

What is CVE-2026-63883?
CVE-2026-63883 is a high-severity vulnerability; its CVE record was published on July 19, 2026. In the Linux kernel, the following vulnerability has been resolved: serial: qcom_geni: fix kfifo underflow when flush precedes DMA completion IRQ When uartflushbuffer() runs before the DMA completion IRQ is delivered, the following race can occur (all steps serialized by uartportlock): 1. DMA…
When was the CVE record for CVE-2026-63883 published?
The CVE record for CVE-2026-63883 was published on July 19, 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 August 5, 2026; the record at its source may have been updated since.
Is CVE-2026-63883 actively exploited?
CVE-2026-63883 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (6th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-63883?
CVE-2026-63883 has a CVSS base score of 7.3 (the CNA's own assessment, by linux; NVD's own analysis pending).
How do I remediate CVE-2026-63883?
A fix for CVE-2026-63883 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-63883 are linked in the Vendor Advisories panel on this page.

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