CVE catalog
CVE-2026-104874
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 s
- Severity
- Medium · CVSS 5.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Published
- Updated
- Source
- [NVD] · [CVE record]
- EPSS
- 0.45% · Oct 25, 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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | python-multidict | sid | 6.4.3-3 | not affected |
| Debian | python-multidict | forky | 6.4.3-3 | not affected |
| Debian | python-multidict | trixie | 6.4.3-1 | not affected |
| Debian | python-multidict | bookworm | 6.0.4-1 | not affected |
| PyPI | multidict | Not reported | 6.7.0 | vulnerable |
| PyPI | multidict | Not reported | 6.7.1 | vulnerable |
| PyPI | multidict | Not reported | 6.8.0 | vulnerable |
| PyPI | multidict | Not reported | 6.9.0 | vulnerable |
| PyPI | multidict | Not reported | 6.9.1 | fixed |
| PyPI | multidict | Not reported | 6.7.0 | vulnerable |
| PyPI | multidict | Not reported | 6.7.1 | vulnerable |
| PyPI | multidict | Not reported | 6.8.0 | vulnerable |
| PyPI | multidict | Not reported | 6.9.0 | vulnerable |
| PyPI | multidict | Not reported | 6.9.1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | python-multidict | source | sid | Not affected | unimportant | Not reported | Not reported |
| Debian | python-multidict | source | forky | Not affected | unimportant | Not reported | Not reported |
| Debian | python-multidict | source | trixie | Not affected | unimportant | Not reported | Not reported |
| Debian | python-multidict | source | bookworm | Not affected | unimportant | Not reported | Not reported |
| PyPI | multidict | PyPI | Not reported | 6.9.1 | Not reported | PYSEC-2026-4244 | Not reported |
| PyPI | multidict | PyPI | Not reported | 6.9.1 | Not reported | GHSA-54P9-H82J-F925 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [python3-multidict]Not affected
Source package: [python-multidict]
Details (2)
6.0.4-1+b1· amd64 · bookwormNot affected
nvd · python-multidict · debian · bookworm
6.0.4-1+b1· arm64 · bookwormNot affected
nvd · python-multidict · debian · bookworm
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_12117-1.json]
- [https://github.com/advisories/GHSA-54p9-h82j-f925]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-104874]
- [https://osv.dev/vulnerability/PYSEC-2026-4244]
- [https://security-tracker.debian.org/tracker/CVE-2026-104874]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-104874.json]
[Debian Security Tracker] · [FIRST EPSS] · [GitHub Advisory Database] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]