Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.10, matching a developer-authored selector that places the general sibling combinator inside :has() repeatedly scans each candidate element's following siblings when the right-hand side is absent, producing quadratic work on attacker-controlled HTML. Applications that evaluate a fixed selector such as div:has(a ~ b) over untrusted markup can have a worker occupied for minutes by a small document, while the adjacent sibling form and trusted-only document processing are not affected in the same way. This issue is fixed in version 2.10.
CVE-2026-126192
MEDIUMPre-NVD 6.36.3ElevatedEG-KEV Tier 3: ElevatedEG-KEV is EchelonGraph's own tiering of exploitation signals from CISA KEV, CISA's SSVC data (Vulnrichment), ransomware data, public exploit-code references and EPSS.Tier 3 is not evidence of exploitation. It means public exploit code is referenced, or CISA's SSVC data says "public PoC", or EPSS ranks the CVE in the top 5%.Signals for this CVE: CISA's SSVC exploitation value: public PoC.EchelonGraph confidence 38%: a heuristic from the tier and the number of signals, not a measured probability.
EchelonGraph scoreLOW confidence
This medium-severity CVE scores 6.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (41st percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Triggered by: Headline CVSS from a secondary CVSS source
Sources: a secondary CVSS source
Also known asEUVD-2026-124557 (ENISA EUVD) · GHSA-4j63-6c4x-wfg4 (GitHub Security Advisories)Source: ENISA EUVD
6.3EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (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: 0.5%CVSS: 6.3Exploit: No code on recordExposed services: Not assessed
A fix is available — apply it.
- CVSS
- 6.3
- EG Score
- 6.3MEDIUMlow confidence
- EG Risk
- 44EG Risk 44/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity63% × 45%Impact severity (EG Severity): CVSS 6.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation40% × 40%EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).Exploitation public PoC (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: A fix is available. Apply it within your standard update timelines. - EPSS PROB
- 0.5%
- EPSS %ILE
- 41st
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (6.3): severity, escalated by confirmed exploitation. This CVE's 6.3 is its impact severity (EG Severity), not escalated.
- EG Severity
- 6.3 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source
- EG Likelihood
- 0.5% within 30 daysSource: FIRST EPSS. FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation public PoC (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.
The score's inputs: 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
November 12, 2026
Last Modified
November 13, 2026
Advisory Details (4)
Auto-updated Nov 13, 2026🔬 Proof of concept available. Patch available. Sources: github, github_commit, github_pr, github_release.
GitHub release Patch Available
2.10
Patch available: facelessuser/soupsieve 2.10
https://github.com/facelessuser/soupsieve/releases/tag/2.10GitHub commit Patch Available
commit ffb88cca745c (facelessuser/soupsieve)
Patch available: facelessuser/soupsieve 2.10 (contains commit ffb88cca745c)
https://github.com/facelessuser/soupsieve/commit/ffb88cca745c591224f74a8e86414a85e8f35fc0GitHub pull request Patch Available
Employ caching to speed up various cases of general sibling combinator
Patch available: facelessuser/soupsieve 2.10 (PR #304 merged 2026-09-23)
https://github.com/facelessuser/soupsieve/pull/304GitHub advisoryMentions a patch (unverified)🟡 PoC Available
General sibling combinator inside :has() matches untrusted HTML in quadratic time · Advisory · facelessuser/soupsieve · GitHub
https://github.com/facelessuser/soupsieve/security/advisories/GHSA-4j63-6c4x-wfg4Vendor Advisories for CVE-2026-126192(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Patch Availability(1)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| pip | soupsieve @ 2.10.0 (fixes <= 2.9.2) | — | ghsa |
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
(1 across 1 ecosystem)
PyPI(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| soupsieve | 0.4 ... 2.9.2 (55 versions) |
| — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 5× in last 7d / 5× 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 its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS → 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.
- 2026-11-13 16:50 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-11-13 02:28 UTCEchelonGraph re-scored
- 2026-11-13 02:28 UTCGHSA enrichmentGHSA-4j63-6c4x-wfg4 · GitHub severity MODERATE
- 2026-11-13 00:46 UTCGHSA enrichmentGHSA-4j63-6c4x-wfg4 · GitHub severity MODERATE
- 2026-11-13 00:42 UTCEchelonGraph re-scored
- 2026-11-13 00:37 UTCEchelonGraph re-scored
- 2026-11-12 18:01 UTCENISA EUVD ID recordedEUVD-2026-124557 · Source: ENISA EUVD
- 2026-11-12 17:30 UTCEchelonGraph re-scored
- 2026-11-12 17:17 UTCEchelonGraph re-scoredFirst assessed: 6.3 MEDIUM
- 2026-11-12 17:16 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-126192?
CVE-2026-126192 is a medium-severity vulnerability; its CVE record was published on November 12, 2026. Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.10, matching a developer-authored selector that places the general sibling combinator inside :has() repeatedly scans each candidate element's following siblings when the right-hand side is absent, producing…
When was the CVE record for CVE-2026-126192 published?
The CVE record for CVE-2026-126192 was published on November 12, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of November 13, 2026; the record at its source may have been updated since.
Is CVE-2026-126192 actively exploited?
CVE-2026-126192 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (41st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-126192?
CVE-2026-126192 has a CVSS base score of 6.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-126192?
A fix for CVE-2026-126192 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-126192 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-126192
Is Your Infrastructure Affected by CVE-2026-126192?
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