Answer in brief
CVE-2026-104874 records a Medium severity (CVSS 5.3) vulnerability in Multidict: Reference leak in CIMultiDict/MultiDict items-view union and subtraction. The current sources do not mark it as known exploited. The current feed maps aio-libs/multidict (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps aio-libs/multidict (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| aio-libs/multidictgeneric | >=6.7.0 <6.9.1 | 6.9.1 |
Published upstream
Oct 2, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 2, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 2, 2026
Multidict is an implementation of a multidict data structure. From 6.7.0 until 6.9.1, the C extension's items-view reflected union operation, operand | d.items(), in multidict_itemsview_or2_impl and subtraction operation, d.items() - operand, in multidict_itemsview_sub1_impl fail to release new key-identity and value references returned for each operand element. Applications that perform these operations over attacker-influenced sequences can leak two strong references per element, and garbage collection cannot reclaim them, so repeated operations can cause unbounded process memory growth and denial of service. Forward union, intersection, non-tuple operand elements, and pure-Python builds are not affected by this reference leak. This issue is fixed in version 6.9.1.
Quoted source text, attributed separately from HOL analysis.