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: 0.6%, top 55% 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
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 7.5Exploit: NoneExposed: 0

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

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)
EPSS
44.8%
KEV
Not listed

Published

July 9, 2026

Last Modified

July 15, 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(1)

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

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 15× in last 7d / 15× 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.

  1. 2026-07-15 18:59 UTCEG score recompute
  2. 2026-07-15 16:57 UTCEPSS rescore
  3. 2026-07-15 16:57 UTCEPSS rescore
  4. 2026-07-15 06:33 UTCEG score recompute
  5. 2026-07-14 18:07 UTCEG score recompute
  6. 2026-07-14 05:41 UTCEG score recompute
  7. 2026-07-13 17:15 UTCEG score recompute
  8. 2026-07-13 04:48 UTCEG score recompute
  9. 2026-07-12 16:22 UTCEG score recompute
  10. 2026-07-12 03:56 UTCEG score recompute
  11. 2026-07-11 15:30 UTCEG score recompute
  12. 2026-07-11 03:04 UTCEG score recompute
  13. 2026-07-10 14:37 UTCEG score recompute
  14. 2026-07-10 02:11 UTCEG score recompute
  15. 2026-07-09 13:45 UTCEG score recompute

Related CVEs(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 15, 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 44.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
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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