{"id":"CVE-2026-44307","aliases":["BELL-CVE-2026-44307","EUVD-2026-29867","GHSA-2h4p-vjrc-8xpq","PYSEC-2026-2617","ROOT-APP-PYPI-CVE-2026-44307","UBUNTU-CVE-2026-44307"],"status":"published","title":"Mako: Path traversal via backslash URI on Windows in TemplateLookup","description":"Mako is a template library written in Python. Prior to 1.3.12, on Windows, a URI using backslash traversal (e.g. \\..\\..\\ secret.txt) bypasses the directory traversal check in Template.__init__ and the posixpath-based normalization in TemplateLookup.get_template(), allowing reads of files outside the configured template directory. This vulnerability is fixed in 1.3.12.","severity":{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00742,"percentile":0.54988,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-22"],"published":"2026-05-06T21:45:16Z","modified":"2026-10-28T02:30:31Z","fixes":[{"ecosystem":"PyPI","package":"mako","fixed_in":["1.3.12"],"sources":["ghsa","osv"]},{"ecosystem":"Root:PyPI","package":"mako","fixed_in":["1.2.4+aikido.1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"mako","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"1.3.11"},{"fixed":"1.3.12"}]}]},{"source":"osv","ecosystem":"PyPI","package":"mako","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.3.12"}]}],"versions":["0.1.0","0.1.1","0.1.10","0.1.2","0.1.3","0.1.4","0.1.5","0.1.6","0.1.7","0.1.8","0.1.9","0.2.0","0.2.1","0.2.2","0.2.3","0.2.4","0.2.5","0.3.0","0.3.1","0.3.2","0.3.3","0.3.4","0.3.5","0.3.6","0.4.0","0.4.1","0.4.2","0.5.0","0.6.0","0.6.1","0.6.2","0.7.0","0.7.1","0.7.2","0.7.3","0.8.0","0.8.1","0.9.0","0.9.1","1.0.0","1.0.1","1.0.10","1.0.11","1.0.12","1.0.13","1.0.14","1.0.2","1.0.3","1.0.4","1.0.5","1.0.6","1.0.7","1.0.8","1.0.9","1.1.0","1.1.1","1.1.2","1.1.3","1.1.4","1.1.5","1.1.6","1.2.0","1.2.1","1.2.2","1.2.3","1.2.4","1.3.0","1.3.1","1.3.10","1.3.11","1.3.2","1.3.3","1.3.4","1.3.5","1.3.6","1.3.7","1.3.8","1.3.9"]},{"source":"osv","ecosystem":"PyPI","package":"mako","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.3.12"}]}],"versions":["0.1.0","0.1.1","0.1.10","0.1.2","0.1.3","0.1.4","0.1.5","0.1.6","0.1.7","0.1.8","0.1.9","0.2.0","0.2.1","0.2.2","0.2.3","0.2.4","0.2.5","0.3.0","0.3.1","0.3.2","0.3.3","0.3.4","0.3.5","0.3.6","0.4.0","0.4.1","0.4.2","0.5.0","0.6.0","0.6.1","0.6.2","0.7.0","0.7.1","0.7.2","0.7.3","0.8.0","0.8.1","0.9.0","0.9.1","1.0.0","1.0.1","1.0.10","1.0.11","1.0.12","1.0.13","1.0.14","1.0.2","1.0.3","1.0.4","1.0.5","1.0.6","1.0.7","1.0.8","1.0.9","1.1.0","1.1.1","1.1.2","1.1.3","1.1.4","1.1.5","1.1.6","1.2.0","1.2.1","1.2.2","1.2.3","1.2.4","1.3.0","1.3.1","1.3.10","1.3.11","1.3.2","1.3.3","1.3.4","1.3.5","1.3.6","1.3.7","1.3.8","1.3.9"]},{"source":"osv","ecosystem":"Root:PyPI","package":"mako","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.2.4+aikido.1"}]}]}],"products":[{"vendor":"sqlalchemy","product":"mako"}],"references":[{"url":"https://github.com/sqlalchemy/mako/security/advisories/GHSA-2h4p-vjrc-8xpq","tags":["x_refsource_CONFIRM","advisory","web","report"]},{"url":"https://github.com/sqlalchemy/mako/issues/435","tags":["x_refsource_MISC","report","web"]},{"url":"https://github.com/sqlalchemy/mako/commit/72e10c573ca0fbcbddd4455abca8ce92a61780d7","tags":["x_refsource_MISC","fix","web","report"]},{"url":"https://github.com/sqlalchemy/mako/releases/tag/rel_1_3_12","tags":["x_refsource_MISC","web","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44307","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-2h4p-vjrc-8xpq","tags":["advisory"]},{"url":"https://docs.bell-sw.com/security/cves/CVE-2026-44307","tags":["advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44307.json","tags":["advisory"]},{"url":"https://github.com/sqlalchemy/mako","tags":["package"]},{"url":"https://pypi.org/project/mako","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2026-44307","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-44307","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-44307","title":"Mako: Path traversal via backslash URI on Windows in TemplateLookup","description":"Mako is a template library written in Python. Prior to 1.3.12, on Windows, a URI using backslash traversal (e.g. \\..\\..\\ secret.txt) bypasses the directory traversal check in Template.__init__ and the posixpath-based normalization in TemplateLookup.get_template(), allowing reads of files outside the configured template directory. This vulnerability is fixed in 1.3.12.","status":"published","published":"2026-05-12T21:53:52.826Z","modified":"2026-05-13T15:00:13.642Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high","assessor":"cna"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T13:42:49.132798Z"}],"euvd":[{"id":"EUVD-2026-29867","description":"Mako is a template library written in Python. Prior to 1.3.12, on Windows, a URI using backslash traversal (e.g. \\..\\..\\ secret.txt) bypasses the directory traversal check in Template.__init__ and the posixpath-based normalization in TemplateLookup.get_template(), allowing reads of files outside the configured template directory. This vulnerability is fixed in 1.3.12.","status":"published","published":"2026-05-12T21:53:52Z","modified":"2026-05-13T15:00:13Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T19:04:33.75998Z"}],"ghsa":[{"id":"GHSA-2h4p-vjrc-8xpq","title":"Mako vulnerable to path traversal via backslash URI on Windows in TemplateLookup","description":"## Summary\n\nOn Windows, a URI using backslash traversal (e.g. `\\..\\..\\ secret.txt`) bypasses the directory traversal check in `Template.__init__` and the `posixpath`-based normalization in `TemplateLookup.get_template()`, allowing reads of files outside the configured template directory.\n\n\n## Details\n\nThe root cause is a mismatch between `posixpath` (used for URI normalization in `get_template()`) and `os.path` (used for file access via `os.path.isfile()` and validation via `os.path.normpath()` in `Template.__init__`). On Windows, `os.path` is `ntpath`, which treats `\\` as a path separator, while `posixpath` treats it as a literal character.\n\nThe vulnerability chain:\n\n1. `get_template()` strips only leading `/` via `re.sub(r\"^\\/+\", \"\", uri)` and normalizes with `posixpath` — backslash `\\` is treated as a literal character, so `\\..\\ secret.txt` passes through with `..` undetected.\n2. `Template.__init__()` validation uses `os.path.normpath()` — on Windows this resolves `\\..\\ secret.txt` to `\\secret.txt`, which does not start with `..`, so the `startswith(\"..\")` check passes.\n3. `os.path.isfile()` on Windows interprets `\\` as a path separator, resolving the `..` traversal and finding files outside the template directory.\n\n### Affected code\n\n- `mako/lookup.py`: `TemplateLookup.get_template()` uses `posixpath.normpath`/`posixpath.join` for path construction but `os.path.isfile()` for existence check\n- `mako/template.py`: `Template.__init__()` URI validation uses `os.path.normpath()` which on Windows resolves backslash traversal to a form that passes the `startswith(\"..\")` guard\n\n## Impact\n\nIf an application passes user-controlled template names or include paths to `TemplateLookup.get_template()`, an attacker on Windows may be able to load and disclose readable files outside the configured template directory. The primary impact is local file disclosure. If the targeted file contains Mako/Python template syntax, it may also be parsed and executed as a template.\n\n## Remediation\n\nThe fix should normalize backslashes to forward slashes early in the URI processing pipeline, before any path operations, to ensure consistent behavior across platforms.","status":"published","published":"2026-05-06T21:45:16Z","modified":"2026-05-13T16:43:11Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:40:09.033429Z"}],"nvd":[{"id":"CVE-2026-44307","description":"Mako is a template library written in Python. Prior to 1.3.12, on Windows, a URI using backslash traversal (e.g. \\..\\..\\ secret.txt) bypasses the directory traversal check in Template.__init__ and the posixpath-based normalization in TemplateLookup.get_template(), allowing reads of files outside the configured template directory. This vulnerability is fixed in 1.3.12.","status":"published","published":"2026-05-12T22:16:37.567Z","modified":"2026-10-26T14:10:00.13Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/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","level":"high","assessor":"secondary"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:12:19.020465Z"}],"osv":[{"id":"CVE-2026-44307","title":"Mako: Path traversal via backslash URI on Windows in TemplateLookup","description":"Mako is a template library written in Python. Prior to 1.3.12, on Windows, a URI using backslash traversal (e.g. \\..\\..\\ secret.txt) bypasses the directory traversal check in Template.__init__ and the posixpath-based normalization in TemplateLookup.get_template(), allowing reads of files outside the configured template directory. This vulnerability is fixed in 1.3.12.","status":"published","published":"2026-05-12T21:53:52.826Z","modified":"2026-10-28T02:30:31.367611477Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T15:45:04.820169Z"},{"id":"GHSA-2h4p-vjrc-8xpq","title":"Mako vulnerable to path traversal via backslash URI on Windows in TemplateLookup","description":"## Summary\n\nOn Windows, a URI using backslash traversal (e.g. `\\..\\..\\ secret.txt`) bypasses the directory traversal check in `Template.__init__` and the `posixpath`-based normalization in `TemplateLookup.get_template()`, allowing reads of files outside the configured template directory.\n\n\n## Details\n\nThe root cause is a mismatch between `posixpath` (used for URI normalization in `get_template()`) and `os.path` (used for file access via `os.path.isfile()` and validation via `os.path.normpath()` in `Template.__init__`). On Windows, `os.path` is `ntpath`, which treats `\\` as a path separator, while `posixpath` treats it as a literal character.\n\nThe vulnerability chain:\n\n1. `get_template()` strips only leading `/` via `re.sub(r\"^\\/+\", \"\", uri)` and normalizes with `posixpath` — backslash `\\` is treated as a literal character, so `\\..\\ secret.txt` passes through with `..` undetected.\n2. `Template.__init__()` validation uses `os.path.normpath()` — on Windows this resolves `\\..\\ secret.txt` to `\\secret.txt`, which does not start with `..`, so the `startswith(\"..\")` check passes.\n3. `os.path.isfile()` on Windows interprets `\\` as a path separator, resolving the `..` traversal and finding files outside the template directory.\n\n### Affected code\n\n- `mako/lookup.py`: `TemplateLookup.get_template()` uses `posixpath.normpath`/`posixpath.join` for path construction but `os.path.isfile()` for existence check\n- `mako/template.py`: `Template.__init__()` URI validation uses `os.path.normpath()` which on Windows resolves backslash traversal to a form that passes the `startswith(\"..\")` guard\n\n## Impact\n\nIf an application passes user-controlled template names or include paths to `TemplateLookup.get_template()`, an attacker on Windows may be able to load and disclose readable files outside the configured template directory. The primary impact is local file disclosure. If the targeted file contains Mako/Python template syntax, it may also be parsed and executed as a template.\n\n## Remediation\n\nThe fix should normalize backslashes to forward slashes early in the URI processing pipeline, before any path operations, to ensure consistent behavior across platforms.","status":"published","published":"2026-05-06T21:45:16Z","modified":"2026-09-10T03:50:45.452547864Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T15:46:34.338541Z"},{"id":"PYSEC-2026-2617","title":"Mako vulnerable to path traversal via backslash URI on Windows in TemplateLookup","description":"## Summary\n\nOn Windows, a URI using backslash traversal (e.g. `\\..\\..\\ secret.txt`) bypasses the directory traversal check in `Template.__init__` and the `posixpath`-based normalization in `TemplateLookup.get_template()`, allowing reads of files outside the configured template directory.\n\n\n## Details\n\nThe root cause is a mismatch between `posixpath` (used for URI normalization in `get_template()`) and `os.path` (used for file access via `os.path.isfile()` and validation via `os.path.normpath()` in `Template.__init__`). On Windows, `os.path` is `ntpath`, which treats `\\` as a path separator, while `posixpath` treats it as a literal character.\n\nThe vulnerability chain:\n\n1. `get_template()` strips only leading `/` via `re.sub(r\"^\\/+\", \"\", uri)` and normalizes with `posixpath` — backslash `\\` is treated as a literal character, so `\\..\\ secret.txt` passes through with `..` undetected.\n2. `Template.__init__()` validation uses `os.path.normpath()` — on Windows this resolves `\\..\\ secret.txt` to `\\secret.txt`, which does not start with `..`, so the `startswith(\"..\")` check passes.\n3. `os.path.isfile()` on Windows interprets `\\` as a path separator, resolving the `..` traversal and finding files outside the template directory.\n\n### Affected code\n\n- `mako/lookup.py`: `TemplateLookup.get_template()` uses `posixpath.normpath`/`posixpath.join` for path construction but `os.path.isfile()` for existence check\n- `mako/template.py`: `Template.__init__()` URI validation uses `os.path.normpath()` which on Windows resolves backslash traversal to a form that passes the `startswith(\"..\")` guard\n\n## Impact\n\nIf an application passes user-controlled template names or include paths to `TemplateLookup.get_template()`, an attacker on Windows may be able to load and disclose readable files outside the configured template directory. The primary impact is local file disclosure. If the targeted file contains Mako/Python template syntax, it may also be parsed and executed as a template.\n\n## Remediation\n\nThe fix should normalize backslashes to forward slashes early in the URI processing pipeline, before any path operations, to ensure consistent behavior across platforms.","status":"published","published":"2026-07-13T15:15:39.881159Z","modified":"2026-07-13T16:32:12.378322773Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T15:52:55.961245Z"},{"id":"UBUNTU-CVE-2026-44307","description":"Mako is a template library written in Python. Prior to 1.3.12, on Windows, a URI using backslash traversal (e.g. \\..\\..\\ secret.txt) bypasses the directory traversal check in Template.__init__ and the posixpath-based normalization in TemplateLookup.get_template(), allowing reads of files outside the configured template directory. This vulnerability is fixed in 1.3.12.","status":"withdrawn","published":"2026-05-12T22:16:00Z","modified":"2026-05-23T19:15:06.21145628Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T16:56:22.075798Z"},{"id":"BELL-CVE-2026-44307","title":"CVE-2026-44307 does not affect BellSoft software","status":"withdrawn","published":"2026-05-21T06:10:54.234171Z","modified":"2026-05-23T07:15:10.802389773Z","updated_at":"2026-11-02T15:28:24.12174Z"},{"id":"ROOT-APP-PYPI-CVE-2026-44307","title":"CVE-2026-44307 in mako - Patched by Root","description":"Root has patched CVE-2026-44307 in the mako package for Root:PyPI. Multiple fixed versions available.","status":"published","published":"2026-09-10T13:06:20Z","modified":"2026-09-10T14:15:04.237699205Z","updated_at":"2026-11-02T15:53:28.259095Z"}]}}