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 57% 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 — 3 sources updated 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
43%
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(8)

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

Patch Availability(7)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatquay/quay-rhel8:17885943762026-09-10redhat
redhatquay/quay-rhel8:17885618412026-09-09redhat
redhatquay/quay-rhel8:17885955742026-09-08redhat
redhatquay/quay-rhel8:17881917552026-09-03redhat
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 11× in last 7d / 59× 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 172 total refreshes for this CVE.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 05:37 UTCEG score recompute
  3. 2026-09-18 05:37 UTCVendor advisory
  4. 2026-09-16 14:08 UTCEPSS rescore
  5. 2026-09-16 05:15 UTCEPSS rescore
  6. 2026-09-13 23:46 UTCEG score recompute
  7. 2026-09-13 23:46 UTCVendor advisory
  8. 2026-09-13 16:47 UTCEPSS rescore
  9. 2026-09-13 08:20 UTCVendor advisory
  10. 2026-09-12 15:50 UTCEG score recompute
  11. 2026-09-12 15:50 UTCVendor advisory
  12. 2026-09-12 03:25 UTCEG score recompute
  13. 2026-09-12 03:25 UTCVendor advisory
  14. 2026-09-11 14:53 UTCEPSS rescore
  15. 2026-09-10 09:35 UTCEPSS rescore
  16. 2026-09-08 22:01 UTCEPSS rescore
  17. 2026-09-07 16:01 UTCEPSS rescore
  18. 2026-09-06 14:00 UTCEG score recompute
  19. 2026-09-06 14:00 UTCVendor advisory
  20. 2026-09-06 13:47 UTCEPSS rescore
  21. 2026-09-05 22:36 UTCEG score recompute
  22. 2026-09-05 22:36 UTCVendor advisory
  23. 2026-09-04 05:06 UTCEPSS rescore
  24. 2026-09-02 14:12 UTCEPSS rescore
  25. 2026-09-01 13:54 UTCEPSS rescore
Show 75 more
  1. 2026-09-01 04:40 UTCEPSS rescore
  2. 2026-08-30 19:22 UTCEG score recompute
  3. 2026-08-30 19:22 UTCVendor advisory
  4. 2026-08-30 19:17 UTCEPSS rescore
  5. 2026-08-30 06:56 UTCEG score recompute
  6. 2026-08-30 06:56 UTCVendor advisory
  7. 2026-08-30 01:22 UTCEPSS rescore
  8. 2026-08-28 21:41 UTCEPSS rescore
  9. 2026-08-27 21:46 UTCEG score recompute
  10. 2026-08-27 21:46 UTCVendor advisory
  11. 2026-08-27 14:25 UTCEPSS rescore
  12. 2026-08-27 01:10 UTCEG score recompute
  13. 2026-08-27 01:10 UTCVendor advisory
  14. 2026-08-26 14:46 UTCEPSS rescore
  15. 2026-08-26 03:53 UTCEG score recompute
  16. 2026-08-26 03:53 UTCVendor advisory
  17. 2026-08-25 13:49 UTCEPSS rescore
  18. 2026-08-25 10:07 UTCVendor advisory
  19. 2026-08-24 20:21 UTCEG score recompute
  20. 2026-08-24 20:21 UTCVendor advisory
  21. 2026-08-24 06:54 UTCVendor advisory
  22. 2026-08-23 18:28 UTCVendor advisory
  23. 2026-08-23 06:03 UTCEG score recompute
  24. 2026-08-23 06:03 UTCVendor advisory
  25. 2026-08-23 00:19 UTCEPSS rescore
  26. 2026-08-22 17:36 UTCVendor advisory
  27. 2026-08-22 05:10 UTCEG score recompute
  28. 2026-08-22 05:10 UTCVendor advisory
  29. 2026-08-21 23:49 UTCEPSS rescore
  30. 2026-08-21 16:43 UTCVendor advisory
  31. 2026-08-21 03:51 UTCEG score recompute
  32. 2026-08-21 03:51 UTCVendor advisory
  33. 2026-08-20 22:55 UTCEPSS rescore
  34. 2026-08-20 15:17 UTCVendor advisory
  35. 2026-08-20 01:50 UTCEG score recompute
  36. 2026-08-20 01:50 UTCVendor advisory
  37. 2026-08-19 17:04 UTCEPSS rescore
  38. 2026-08-19 09:16 UTCVendor advisory
  39. 2026-08-18 20:43 UTCEG score recompute
  40. 2026-08-18 20:43 UTCVendor advisory
  41. 2026-08-18 13:48 UTCEPSS rescore
  42. 2026-08-18 02:55 UTCEG score recompute
  43. 2026-08-18 02:55 UTCVendor advisory
  44. 2026-08-17 13:47 UTCEPSS rescore
  45. 2026-08-17 13:36 UTCVendor advisory
  46. 2026-08-17 01:11 UTCEG score recompute
  47. 2026-08-17 01:11 UTCVendor advisory
  48. 2026-08-16 14:56 UTCEPSS rescore
  49. 2026-08-16 12:45 UTCEG score recompute
  50. 2026-08-16 12:45 UTCVendor advisory
  51. 2026-08-16 02:14 UTCEPSS rescore
  52. 2026-08-16 00:20 UTCVendor advisory
  53. 2026-08-15 11:54 UTCEG score recompute
  54. 2026-08-15 11:54 UTCVendor advisory
  55. 2026-08-15 01:30 UTCEPSS rescore
  56. 2026-08-14 23:28 UTCVendor advisory
  57. 2026-08-14 11:03 UTCVendor advisory
  58. 2026-08-13 22:37 UTCEG score recompute
  59. 2026-08-13 22:37 UTCVendor advisory
  60. 2026-08-13 22:00 UTCEPSS rescore
  61. 2026-08-13 10:12 UTCVendor advisory
  62. 2026-08-12 21:47 UTCEG score recompute
  63. 2026-08-12 21:47 UTCVendor advisory
  64. 2026-08-12 13:51 UTCEPSS rescore
  65. 2026-08-12 09:21 UTCVendor advisory
  66. 2026-08-11 20:55 UTCEG score recompute
  67. 2026-08-11 20:55 UTCVendor advisory
  68. 2026-08-11 08:30 UTCEG score recompute
  69. 2026-08-11 08:30 UTCVendor advisory
  70. 2026-08-11 00:00 UTCEPSS rescore
  71. 2026-08-10 20:04 UTCVendor advisory
  72. 2026-08-10 07:39 UTCVendor advisory
  73. 2026-08-09 19:13 UTCEG score recompute
  74. 2026-08-09 19:13 UTCVendor advisory
  75. 2026-08-09 13:46 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 56.8% 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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