CVE-2026-15709

HIGHPre-NVD 7.57.5
EchelonGraph scoreMEDIUM confidence

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

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-07-14. A secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Elevated
7.5EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.9%CVSS: 7.5Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

A flaw was found in libsoup's WebSocket implementation when using the permessage-deflate extension. The extension's decompression loop (inflate()) processes data in chunks without enforcing an upper boundary limit on the output buffer size. While libsoup limits the incoming compressed frame size via max_incoming_payload_size, it fails to track or limit memory allocation during decompression. A separate check for decompressed size (max_total_message_size) exists but executes only after inflation is complete, and it is entirely disabled by default for client connections. A remote, unauthenticated attacker can exploit this by sending a small, highly compressed payload (a decompression bomb), causing unbounded memory allocation that triggers an Out-of-Memory (OOM) crash and a Denial of Service (DoS).

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
65
EG Risk 65/100

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)
Severity75% × 45%
The EG Score, 7.5 of 10.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (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 at low or medium mission impact and sooner than that at high.
EPSS PROB
0.9%
EPSS %ILE
58th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (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)14 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (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 24, 2026

Advisory Details (3)

Auto-updated Jul 15, 2026
Patch available. Sources: redhat.
Web page

WebSocket Decompression Bomb (#511) · Issues · GNOME / libsoup · GitLab

https://gitlab.gnome.org/GNOME/libsoup/-/issues/511
Red Hat

2499922 – (CVE-2026-15709) CVE-2026-15709 SoupWebsocketExtensionDeflate: libsoup: libsoup: WebSocket permessage-deflate Unbounded Decompression Remote Denial of Service

https://bugzilla.redhat.com/show_bug.cgi?id=2499922
Red HatMentions a patch (unverified)

cve-details

https://access.redhat.com/security/cve/CVE-2026-15709

Vendor Advisories for CVE-2026-15709(8)

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

Patch Availability(9)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatlibsoup3-0:3.6.5-3.el10_0.172026-09-24redhat
redhatlibsoup-0:2.62.3-2.el8_6.102026-09-23redhat
redhatlibsoup-0:2.62.3-2.el8_4.102026-09-23redhat
redhatlibsoup-0:2.62.3-3.el8_8.112026-09-22redhat
redhatlibsoup-0:2.72.0-8.el9_2.132026-09-21redhat
redhatlibsoup-0:2.72.0-8.el9_4.122026-09-21redhat
redhatlibsoup-0:2.72.0-10.el9_6.92026-09-17redhat
redhatlibsoup-0:2.72.0-16.el9_8.32026-09-16redhat
redhatlibsoup3-0:3.6.5-3.el10_2.142026-09-16redhat

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

(6 across 4 ecosystems)
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
libsoup2.42.74.3-1 ... 2.74.3-9 (16 versions)
  • every version on: no fix on record
—
libsoup33.2.2-2 ... 3.6.6-1 (35 versions)
  • every version on: no fix on record
—
Debian:13(2)
PackageVulnerable rangeFix by version rangeDependents
libsoup2.42.74.3-10.1, 2.74.3-11
  • every version on: no fix on record
—
libsoup33.6.5-3 ... 3.6.6-1 (8 versions)
  • every version on: no fix on record
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
libsoup2.42.72.0-2 ... 2.74.3-9 (28 versions)
  • every version on: no fix on record
—
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.

Additional Vendor Advisories

(3)

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 / 80× 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 256 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 156 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 0.9% · 58th percentile
  2. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  3. 2026-10-12 16:31 UTCEG score recompute
  4. 2026-10-11 20:09 UTCEG score recompute
  5. 2026-10-11 17:22 UTCEG score recompute
  6. 2026-10-11 14:55 UTCEG score recompute
  7. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  8. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  9. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  10. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  11. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  12. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  13. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  14. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  15. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  16. 2026-10-01 12:53 UTCEG score recompute
  17. 2026-10-01 12:53 UTCVendor advisory
  18. 2026-10-01 12:53 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  19. 2026-09-30 15:02 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  20. 2026-09-29 15:20 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  21. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  22. 2026-09-28 08:54 UTCEG score recompute
  23. 2026-09-28 08:54 UTCVendor advisory
  24. 2026-09-28 08:54 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  25. 2026-09-27 13:47 UTCEPSS rescoreEPSS 0.9% · 57th percentile
Show 75 more
  1. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  2. 2026-09-24 10:19 UTCEG score recompute
  3. 2026-09-24 10:19 UTCVendor advisory
  4. 2026-09-24 10:19 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  5. 2026-09-24 09:49 UTCEG score recompute
  6. 2026-09-24 09:49 UTCVendor advisory
  7. 2026-09-24 09:49 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  8. 2026-09-24 09:01 UTCEG score recompute
  9. 2026-09-24 09:01 UTCVendor advisory
  10. 2026-09-24 09:01 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  11. 2026-09-23 09:17 UTCEG score recompute
  12. 2026-09-23 09:17 UTCVendor advisory
  13. 2026-09-23 09:17 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  14. 2026-09-23 08:21 UTCEG score recompute
  15. 2026-09-23 08:21 UTCVendor advisory
  16. 2026-09-23 08:21 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  17. 2026-09-23 03:29 UTCEG score recompute
  18. 2026-09-23 03:29 UTCVendor advisory
  19. 2026-09-23 03:29 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  20. 2026-09-22 08:35 UTCEG score recompute
  21. 2026-09-22 08:35 UTCVendor advisory
  22. 2026-09-22 08:35 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  23. 2026-09-22 07:31 UTCEG score recompute
  24. 2026-09-22 07:31 UTCVendor advisory
  25. 2026-09-22 07:31 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  26. 2026-09-21 15:24 UTCEG score recompute
  27. 2026-09-21 15:24 UTCVendor advisory
  28. 2026-09-21 15:24 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  29. 2026-09-21 14:25 UTCEG score recompute
  30. 2026-09-21 14:25 UTCVendor advisory
  31. 2026-09-21 14:25 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  32. 2026-09-21 06:23 UTCEG score recompute
  33. 2026-09-21 06:23 UTCVendor advisory
  34. 2026-09-21 06:23 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  35. 2026-09-21 05:55 UTCEG score recompute
  36. 2026-09-21 05:55 UTCVendor advisory
  37. 2026-09-21 05:55 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  38. 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  39. 2026-09-18 10:01 UTCEG score recompute
  40. 2026-09-18 10:01 UTCVendor advisory
  41. 2026-09-18 10:01 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  42. 2026-09-17 19:28 UTCEG score recompute
  43. 2026-09-17 19:28 UTCVendor advisory
  44. 2026-09-17 19:28 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  45. 2026-09-17 19:10 UTCEG score recompute
  46. 2026-09-17 19:10 UTCVendor advisory
  47. 2026-09-17 19:10 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  48. 2026-09-16 19:21 UTCEG score recompute
  49. 2026-09-16 19:21 UTCVendor advisory
  50. 2026-09-16 19:21 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  51. 2026-09-16 18:27 UTCEG score recompute
  52. 2026-09-16 18:27 UTCVendor advisory
  53. 2026-09-16 18:27 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  54. 2026-09-16 14:07 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  55. 2026-09-16 05:14 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  56. 2026-09-13 23:16 UTCEG score recompute
  57. 2026-09-13 23:16 UTCVendor advisory
  58. 2026-09-13 23:16 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  59. 2026-09-13 16:46 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  60. 2026-09-13 07:39 UTCEG score recompute
  61. 2026-09-13 07:39 UTCVendor advisory
  62. 2026-09-13 07:39 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  63. 2026-09-12 15:00 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  64. 2026-09-12 13:12 UTCVendor advisory
  65. 2026-09-12 13:12 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  66. 2026-09-11 21:55 UTCEG score recompute
  67. 2026-09-11 21:55 UTCVendor advisory
  68. 2026-09-11 21:55 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  69. 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  70. 2026-09-11 09:36 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  71. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  72. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  73. 2026-09-08 01:10 UTCEG score recompute
  74. 2026-09-08 01:10 UTCGHSA enrichmentGHSA-gv2g-7h3v-q5f3 · GitHub severity HIGH · GitHub CVSS 7.5
  75. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.8% · 53rd percentile

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

Same vendor

2 shown

redhat:RHSA-2026:68234 · redhat:RHSA-2026:68235

Frequently asked(5)

What is CVE-2026-15709?
CVE-2026-15709 is a high-severity vulnerability; its CVE record was published on July 14, 2026. A flaw was found in libsoup's WebSocket implementation when using the permessage-deflate extension. The extension's decompression loop (inflate()) processes data in chunks without enforcing an upper boundary limit on the output buffer size. While libsoup limits the incoming compressed frame size…
When was CVE-2026-15709 made public?
CVE-2026-15709 was made public on July 14, 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 24, 2026; the record at its source may have been updated since.
Is CVE-2026-15709 actively exploited?
CVE-2026-15709 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.9% probability of exploitation in the next 30 days (58th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-15709?
CVE-2026-15709 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-15709?
A fix for CVE-2026-15709 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-15709 are linked in the Vendor Advisories panel on this page.

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