CVE-2026-12478

MEDIUMPre-NVD 4.84.8
EchelonGraph scoreMEDIUM confidence

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

Score 4.8 from GitHub Security Advisory published 2026-07-14. A secondary CVSS source baseline 4.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
4.8EG
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: 4.8Exploit: None knownExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

The fix for CVE-2026-0716 (commit 6ff7ef0, libsoup 3.6.6) placed the integer overflow guard inside the if (masked) block, leaving unmasked server-to-client frames unprotected. A malicious WebSocket server can send a crafted unmasked frame with a payload length near UINT64_MAX to trigger an OOB read in a libsoup-based client when max_incoming_payload_size is set to 0.

CVSS v3
4.8
EG Score
4.8MEDIUMmedium confidence
EG Risk
22
EG Risk 22/100

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed (value × EchelonGraph’s weight)
Severity48% × 45%
The EG Score, 4.8 of 10.
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: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
EPSS PROB
0.2%
EPSS %ILE
14th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.

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 14, 2026

Last Modified

September 16, 2026

Advisory Details (4)

Auto-updated Jul 14, 2026
No fix on record yet. Sources: redhat.
Web page

websocket: Fix out-of-bounds read when reading unmasked frame (!518) · Merge requests · GNOME / libsoup · GitLab

https://gitlab.gnome.org/GNOME/libsoup/-/merge_requests/518
Red Hat

2489655 – (CVE-2026-12478) CVE-2026-12478 libsoup: Incomplete fix for CVE-2026-0716: Out-of-bounds read in libsoup WebSocket frame processing (unmasked path)

https://bugzilla.redhat.com/show_bug.cgi?id=2489655
Red HatMentions a patch (unverified)

cve-details

https://access.redhat.com/security/cve/cve-2026-0716
Red HatMentions a patch (unverified)

cve-details

https://access.redhat.com/security/cve/CVE-2026-12478

Vendor Advisories for CVE-2026-12478(1)

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

Affected Packages

(1 across 1 ecosystem)
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
libsoup33.6.5-3 ... 3.6.6-1 (8 versions)
  • every version on: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 40× 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 183 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 83 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  2. 2026-10-12 16:36 UTCEG score recompute
  3. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  4. 2026-10-11 20:12 UTCEG score recompute
  5. 2026-10-11 18:24 UTCEG score recompute
  6. 2026-10-11 14:57 UTCEG score recompute
  7. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  8. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  9. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  10. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  11. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  12. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  13. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  14. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  15. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  16. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  17. 2026-10-01 13:28 UTCEG score recompute
  18. 2026-10-01 13:28 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  19. 2026-09-30 15:02 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  20. 2026-09-29 15:20 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  21. 2026-09-28 13:50 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  22. 2026-09-28 09:24 UTCEG score recompute
  23. 2026-09-28 09:24 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  24. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  25. 2026-09-24 09:56 UTCEG score recompute
Show 75 more
  1. 2026-09-24 09:56 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  2. 2026-09-23 13:47 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  3. 2026-09-23 03:59 UTCEG score recompute
  4. 2026-09-23 03:59 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  5. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  6. 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  7. 2026-09-18 04:57 UTCEG score recompute
  8. 2026-09-18 04:57 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  9. 2026-09-16 09:31 UTCEG score recompute
  10. 2026-09-16 09:31 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  11. 2026-09-16 08:30 UTCEG score recompute
  12. 2026-09-16 08:30 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  13. 2026-09-16 05:14 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  14. 2026-09-15 20:47 UTCEG score recompute
  15. 2026-09-15 20:47 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  16. 2026-09-14 06:47 UTCEG score recompute
  17. 2026-09-14 06:47 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  18. 2026-09-13 16:46 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  19. 2026-09-13 07:56 UTCEG score recompute
  20. 2026-09-13 07:56 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  21. 2026-09-12 15:00 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  22. 2026-09-12 01:47 UTCEG score recompute
  23. 2026-09-12 01:47 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  24. 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  25. 2026-09-11 09:36 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  26. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  27. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  28. 2026-09-08 01:49 UTCEG score recompute
  29. 2026-09-08 01:49 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  30. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  31. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  32. 2026-09-05 21:19 UTCEG score recompute
  33. 2026-09-05 21:19 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  34. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  35. 2026-09-02 14:11 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  36. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  37. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  38. 2026-08-31 05:47 UTCEG score recompute
  39. 2026-08-31 05:47 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  40. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  41. 2026-08-30 05:25 UTCEG score recompute
  42. 2026-08-30 05:25 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  43. 2026-08-30 01:21 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  44. 2026-08-28 21:40 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  45. 2026-08-27 23:54 UTCEG score recompute
  46. 2026-08-27 23:54 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  47. 2026-08-27 14:24 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  48. 2026-08-27 00:44 UTCEG score recompute
  49. 2026-08-27 00:44 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  50. 2026-08-26 01:53 UTCEG score recompute
  51. 2026-08-26 01:53 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  52. 2026-08-25 13:48 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  53. 2026-08-25 02:39 UTCEG score recompute
  54. 2026-08-25 02:38 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  55. 2026-08-24 03:48 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  56. 2026-08-23 04:37 UTCEG score recompute
  57. 2026-08-23 04:37 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  58. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  59. 2026-08-22 05:47 UTCEG score recompute
  60. 2026-08-22 05:47 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  61. 2026-08-21 23:48 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  62. 2026-08-21 06:57 UTCEG score recompute
  63. 2026-08-21 06:57 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  64. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  65. 2026-08-20 08:06 UTCEG score recompute
  66. 2026-08-20 08:06 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  67. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  68. 2026-08-19 09:16 UTCEG score recompute
  69. 2026-08-19 09:16 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  70. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  71. 2026-08-18 10:27 UTCEG score recompute
  72. 2026-08-18 10:27 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  73. 2026-08-17 10:09 UTCEG score recompute
  74. 2026-08-17 10:09 UTCGHSA enrichmentGHSA-6jpc-6452-qwq2 · GitHub CVSS 4.8
  75. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.2% · 16th percentile

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-12478?
CVE-2026-12478 is a medium-severity vulnerability; its CVE record was published on July 14, 2026. The fix for CVE-2026-0716 (commit 6ff7ef0, libsoup 3.6.6) placed the integer overflow guard inside the if (masked) block, leaving unmasked server-to-client frames unprotected. A malicious WebSocket server can send a crafted unmasked frame with a payload length near UINT64MAX to trigger an OOB read…
When was CVE-2026-12478 made public?
CVE-2026-12478 was made public on April 27, 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 July 14, 2026. EchelonGraph's copy of the record carries a last-modified date of September 16, 2026; the record at its source may have been updated since.
Is CVE-2026-12478 actively exploited?
CVE-2026-12478 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (14th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-12478?
CVE-2026-12478 has a CVSS base score of 4.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-12478?
No fix for CVE-2026-12478 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-12478 are linked in the Vendor Advisories panel on this page.

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