CVE-2026-49477

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5%, top 58% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — Patch released this weekElevated
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 7.5Exploit: Elevated riskExposed: 0

A fix is available — apply it.

Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.8.4, the CSS selector parser in soupsieve contains a regular expression vulnerable to catastrophic backtracking when processing an attribute selector with an unterminated quoted value in soupsieve/css_parser.py, allowing an attacker who can supply untrusted CSS selector strings to soupsieve.compile() or Beautiful Soup .select() / .select_one() to cause CPU exhaustion and denial of service. This issue is fixed in version 2.8.4.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
65(Attend)
EG Risk 65/100SSVC: Attend

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
Severity75% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
1%
EPSS %ILE
42%
KEV
Not listed

Published

July 9, 2026

Last Modified

July 28, 2026

Advisory Details (3)

Auto-updated Jul 15, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github.
github Patch Available🟡 PoC Available

Regular Expression Denial of Service (ReDoS) in soupsieve Selector Parser · Advisory · facelessuser/soupsieve · GitHub

https://github.com/facelessuser/soupsieve/security/advisories/GHSA-836r-79rf-4m37
github_release Patch Available

2.8.4

Patch available: facelessuser/soupsieve 2.8.4

https://github.com/facelessuser/soupsieve/releases/tag/2.8.4
github_commit Patch Available

commit eb4397618709 (facelessuser/soupsieve)

Patch available: facelessuser/soupsieve 2.8.4 (contains commit eb4397618709)

https://github.com/facelessuser/soupsieve/commit/eb4397618709186c109400448c6043b728217dc3

Vendor Advisories for CVE-2026-49477(4)

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

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatrhoai/odh-workbench-jupyter-trustyai-cpu-py312-rhel9:17870735932026-08-27redhat
redhatpython-rpds-py-main-2026.6.3-1.hum12026-07-01redhat
redhatpython-attrs-main-26.1.0-3.hum12026-06-07redhat

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

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
soupsieve2.2.1-1 ... 2.8.4-1 (15 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
soupsieve2.3.2-1 ... 2.8.4-1 (11 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
soupsieve2.7-1, 2.7-2, 2.8.1-1, 2.8.3-1, 2.8.4-1——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
soupsieve2.7-1, 2.7-2, 2.8.1-1, 2.8.3-12.8.4-1—
PyPI(1)
PackageVulnerable rangeFixed inDependents
soupsieve0.4 ... 2.8.3 (51 versions)2.8.4—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 18× in last 7d / 105× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

Showing the most recent 100 of 143 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-49477?
CVE-2026-49477 is a high vulnerability published on July 9, 2026. Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.8.4, the CSS selector parser in soupsieve contains a regular expression vulnerable to catastrophic backtracking when processing an attribute selector with an unterminated quoted value in…
When was CVE-2026-49477 disclosed?
CVE-2026-49477 was first published in the National Vulnerability Database on July 9, 2026, with the most recent update on July 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-49477 actively exploited?
CVE-2026-49477 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 57.9% of all scored CVEs.
What is the CVSS score of CVE-2026-49477?
CVE-2026-49477 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-49477?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-49477, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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