EUVD-2026-76162
GHSA-rj44-3777-mh5x
Severity by source
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
AC:H reflects two required preconditions (no-link system plus None-returning filter); no attacker privileges needed; user must actively extract the archive.
Primary rating from Vendor (PSF).
CVSS VectorVendor: PSF
Lifecycle Timeline
3DescriptionCVE.org
When tarfile extracts a link on a system that doesn't support links, it falls back to extracting a member from the archive. In this case, the filter function is run twice: once for the extracted member, and once with name set to the location of the link. For one of the calls, the return value was ignored. Instead, the member should be skipped if either call returns None.
AnalysisAI
Path traversal in CPython's tarfile module allows an attacker to write files outside the intended extraction directory by exploiting a filter bypass in the link-fallback code path. On systems that do not support symbolic or hard links, tarfile falls back to extracting the link target as a regular archive member; in this fallback path the filter function is called a second time but its return value is discarded, so a filter that returns None to reject a dangerous member silently fails to block extraction. …
Unlock full vulnerability intelligence
- Risk assessment & exploitation conditions
- Attack chain visualization
- Remediation with exact patch versions
- Threat intelligence from 22 sources
- Personal watchlist & email alerts
Free forever · No credit card required
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires all of the following simultaneously: (1) the target host does not support symbolic or hard links - this triggers the link-fallback code path that contains the bug; (2) the calling code uses a tarfile filter function that returns None to reject members (rather than raising a FilterError); and (3) the victim actively invokes tarfile extraction on an attacker-controlled archive. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 4.0 score of 5.7 with vector AV:N/AC:L/AT:P/PR:L/UI:A accurately reflects a moderate, condition-dependent risk. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | Full exploit scenario with step-by-step reproduction available after sign-in. |
| Remediation | The upstream fix is available as GitHub PR #157266 (https://github.com/python/cpython/pull/157266); apply the patch once it lands in an official CPython release and upgrade to that version. … Detailed patch versions, workarounds, and compensating controls in full report. |
Threat intelligence, references, and detailed analysis are available after sign-in.
Integrity bypass in CPython's stringprep module causes divergent domain name normalization when processing international
CPython decompression modules (lzma, bz2, gzip) allow memory corruption via use-after-free when decompressor instances a
Out-of-bounds buffer write in CPython's asyncio.ProactorEventLoop (Windows only) allows remote attackers to trigger memo
Denial of service in CPython's tarfile module allows remote attackers to trigger an infinite loop by supplying a crafted
Stack-based buffer overflow in CPython's bz2.BZ2Decompressor allows remote attackers to crash Python applications by sen
Path traversal in CPython's tarfile module allows a crafted tar archive to bypass the 'data' and 'tar' extraction filter
Command injection in CPython's webbrowser.open() API bypasses previous CVE-2026-4519 mitigation via specially crafted UR
The webbrowser.open() API in CPython accepts URLs with leading dashes, which certain web browsers interpret as command-l
Path traversal in CPython's tarfile module allows malicious tar archives to bypass the data_filter safety mechanism and
CPython's tarfile module on POSIX platforms creates empty directories outside the intended extraction destination when p
XML parsers in CPython's xml.parsers.expat and xml.etree.ElementTree modules use insufficient entropy for Expat hash-flo
Denial-of-service via quadratic algorithmic complexity in CPython's unicodedata.normalize() affects all CPython versions
Same weakness CWE-22 – Path Traversal
View allSame technique Path Traversal
View allShare
External POC / Exploit Code
Leaving vuln.today