CVE-2022-2309NULL Pointer Dereference in lxml/lxml
- 5.3MediumCVSS base score
- 2.4%Exploitation in 30 daysEPSS · top 15% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
NULL Pointer Dereference allows attackers to cause a denial of service (or application crash). This only applies when lxml is used together with libxml2 2.9.10 through 2.9.14. libxml2 2.9.9 and earlier are not affected. It allows triggering crashes through forged input data, given a vulnerable code sequence in the application. The vulnerability is caused by the iterwalk function (also used by the canonicalize function). Such code shouldn't be in wide-spread use, given that parsing + iterwalk would usually be replaced with the more efficient iterparse function. However, an XML converter that serialises to C14N would also be vulnerable, for example, and there are legitimate use cases for this code sequence. If untrusted input is received (also remotely) and processed via iterwalk function, a crash can be triggered.
Timeline
ID reserved
By @huntrdev
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| @huntrdevCNA (assigner) | 3.0 | Medium5.3 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 2.4% · top 15% of all CVEs (15 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
References
References7
- https://huntr.dev/bounties/8264e74f-edda-4c40-9956-49de635105ba (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/lxml/lxml/commit/86368e9cf70a0ad23cccd5ee32de847149af0c6f (opens in a new tab)x_refsource_MISCx_transferred
- GLSA-202208-06 (opens in a new tab)vendor-advisoryx_refsource_GENTOOx_transferred
- https://security.netapp.com/advisory/ntap-20220915-0006/ (opens in a new tab)x_refsource_CONFIRMx_transferred
- FEDORA-2022-ed0eeb6a20 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- FEDORA-2022-ed17f59c1d (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- https://lists.debian.org/debian-lts-announce/2024/09/msg00021.html (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2022-0148 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-wrxv-2j5q-m38w (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2022-2309)Record last updated .