CVE-2025-11468
published 2026-01-20CVE-2025-11468: When folding a long comment in an email header containing exclusively unfoldable characters, the parenthesis would not be preserved. This could be used for…
PriorityP429medium5.7CVSS 4.0
AVNACLATPPRHUIPVCNVIHVANSCNSINSANEXCRXIRXARXMAVXMACXMATXMPRXMUIXMVCXMVIXMVAXMSCXMSIXMSAXSXAUXRXVXREXUX
EPSS
0.55%
42.2th percentile
When folding a long comment in an email header containing exclusively unfoldable characters, the parenthesis would not be preserved. This could be used for injecting headers into email messages where addresses are user-controlled and not sanitized.
Affected
13 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | jython | < python3.13 3.13.12-1 (forky) | python3.13 3.13.12-1 (forky) |
| debian | pypy3 | < python3.13 3.13.12-1 (forky) | python3.13 3.13.12-1 (forky) |
| debian | python2.7 | < python3.13 3.13.12-1 (forky) | python3.13 3.13.12-1 (forky) |
| debian | python3.11 | < python3.13 3.13.12-1 (forky) | python3.13 3.13.12-1 (forky) |
| debian | python3.13 | < python3.13 3.13.12-1 (forky) | python3.13 3.13.12-1 (forky) |
| debian | python3.14 | < python3.13 3.13.12-1 (forky) | python3.13 3.13.12-1 (forky) |
| debian | python3.9 | < python3.13 3.13.12-1 (forky) | python3.13 3.13.12-1 (forky) |
| python_software_foundation | cpython | < 3.10.20 | 3.10.20 |
| python_software_foundation | cpython | >= 3.11.0 < 3.11.15 | 3.11.15 |
| python_software_foundation | cpython | >= 3.12.0 < 3.12.13 | 3.12.13 |
| python_software_foundation | cpython | >= 3.13.0 < 3.13.12 | 3.13.12 |
| python_software_foundation | cpython | >= 3.14.0 < 3.14.3 | 3.14.3 |
| python_software_foundation | cpython | >= 3.15.0a1 < 3.15.0a6 | 3.15.0a6 |
CVSS provenance
nvdv4.05.7MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/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
osv5.7MEDIUM
vendor_debian5.7LOW
vendor_redhat5.7MEDIUM
vendor_ubuntu5.3MEDIUM
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Ubuntu
Python 2.7 vulnerabilities
vendor_ubuntu·2026-03-19·CVSS 5.3
CVE-2025-12084 [MEDIUM] Python 2.7 vulnerabilities
Title: Python 2.7 vulnerabilities
Summary: Several security issues were fixed in python2.7
USN-8018-1 fixed CVE-2025-12084, CVE-2025-15282, CVE-2026-0672,
CVE-2026-0865 for python3. This update provides the corresponding updates
for python2.7.
Original advisory details:
Denis Ledoux discovered that Python incorrectly parsed email message
headers. An attacker could possibly use this issue to inject arbitrary
headers into email messages. This issue only affected python3.6,
python3.7, python3.8, python3.9, python3.10, python3.11, python3.12,
python3.13, and python3.14 packages. (CVE-2025-11468)
Jacob Walls, Shai Berger, and Natalia Bidart discovered that Python
inefficiently parsed XML input with quadratic complexity. An attacker
could possibly use this issue to cause a denial of service
Ubuntu
Python regression
vendor_ubuntu·2026-03-09·CVSS 5.3
CVE-2025-15367 [MEDIUM] Python regression
Title: Python regression
Summary: USN-8018-1 introduced a regression in Python
USN-8018-1 fixed vulnerabilities in python3. That update introduced
regressions. The patches for CVE-2025-15366 and CVE-2025-15367 caused
behavior regressions in IMAP and POP3 handling, which upstream chose to
avoid by not backporting them. Additionally, the patch for CVE-2026-0865
incorrectly rejected horizontal tabs in wsgiref headers. This update fixes
these problems.
We apologize for the inconvenience.
Original advisory details:
Denis Ledoux discovered that Python incorrectly parsed email message
headers. An attacker could possibly use this issue to inject arbitrary
headers into email messages. This issue only affected python3.6,
python3.7, python3.8, python3.9, python3.10, python3.11, python3.12,
pytho
Ubuntu
Python vulnerabilities
vendor_ubuntu·2026-02-05·CVSS 5.3
CVE-2025-15366 [MEDIUM] Python vulnerabilities
Title: Python vulnerabilities
Summary: Several security issues were fixed in Python.
Denis Ledoux discovered that Python incorrectly parsed email message
headers. An attacker could possibly use this issue to inject arbitrary
headers into email messages. This issue only affected python3.6, python3.7,
python3.8, python3.9, python3.10, python3.11, python3.12, python3.13, and
python3.14 packages. (CVE-2025-11468)
Jacob Walls, Shai Berger, and Natalia Bidart discovered that Python
inefficiently parsed XML input with quadratic complexity. An attacker could
possibly use this issue to cause a denial of service. (CVE-2025-12084)
It was discovered that Python incorrectly parsed malicious plist files. An
attacker could possibly use this issue to cause Python to use excessive
resources, leading to
Red Hat
cpython: Missing character filtering in Python
vendor_redhat·2026-01-20·CVSS 5.7
CVE-2025-11468 [MEDIUM] CWE-140 cpython: Missing character filtering in Python
cpython: Missing character filtering in Python
When folding a long comment in an email header containing exclusively unfoldable characters, the parenthesis would not be preserved. This could be used for injecting headers into email messages where addresses are user-controlled and not sanitized.
Missing character filtering has been discovered in Python. When folding a long comment in an email header containing exclusively unfoldable characters, the parenthesis would not be preserved. This could be used for injecting headers into email messages where addresses are user-controlled and not sanitized.
Mitigation: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applica
Debian
CVE-2025-11468: jython - When folding a long comment in an email header containing exclusively unfoldable...
vendor_debian·2025·CVSS 5.7
CVE-2025-11468 [MEDIUM] CVE-2025-11468: jython - When folding a long comment in an email header containing exclusively unfoldable...
When folding a long comment in an email header containing exclusively unfoldable characters, the parenthesis would not be preserved. This could be used for injecting headers into email messages where addresses are user-controlled and not sanitized.
Scope: local
bookworm: resolved
bullseye: resolved
forky: resolved
sid: resolved
trixie: resolved
OSV
python2.7 vulnerabilities
osv·2026-03-19·CVSS 5.7
CVE-2025-12084 [MEDIUM] python2.7 vulnerabilities
python2.7 vulnerabilities
USN-8018-1 fixed CVE-2025-12084, CVE-2025-15282, CVE-2026-0672,
CVE-2026-0865 for python3. This update provides the corresponding updates
for python2.7.
Original advisory details:
Denis Ledoux discovered that Python incorrectly parsed email message
headers. An attacker could possibly use this issue to inject arbitrary
headers into email messages. This issue only affected python3.6,
python3.7, python3.8, python3.9, python3.10, python3.11, python3.12,
python3.13, and python3.14 packages. (CVE-2025-11468)
Jacob Walls, Shai Berger, and Natalia Bidart discovered that Python
inefficiently parsed XML input with quadratic complexity. An attacker
could possibly use this issue to cause a denial of service.
(CVE-2025-12084)
It was discovered that Python incorrectly pars
OSV
python3.4, python3.5, python3.6, python3.7, python3.8, python3.9,
python3.10, python3.11, python3.12, python3.13, python3.14 regression
osv·2026-03-09·CVSS 5.7
CVE-2025-15366 [MEDIUM] python3.4, python3.5, python3.6, python3.7, python3.8, python3.9,
python3.10, python3.11, python3.12, python3.13, python3.14 regression
python3.4, python3.5, python3.6, python3.7, python3.8, python3.9,
python3.10, python3.11, python3.12, python3.13, python3.14 regression
USN-8018-1 fixed vulnerabilities in python3. That update introduced
regressions. The patches for CVE-2025-15366 and CVE-2025-15367 caused
behavior regressions in IMAP and POP3 handling, which upstream chose to
avoid by not backporting them. Additionally, the patch for CVE-2026-0865
incorrectly rejected horizontal tabs in wsgiref headers. This update fixes
these problems.
We apologize for the inconvenience.
Original advisory details:
Denis Ledoux discovered that Python incorrectly parsed email message
headers. An attacker could possibly use this issue to inject arbitrary
headers into email messages. This issue only affected python3.6,
python3.7, python3
OSV
python3.14, python3.13, python3.12, python3.11, python3.10, python3.9,
python3.8, python3.7, python3.6, python3.5, python3.4 vulnerabilities
osv·2026-02-05·CVSS 5.7
CVE-2025-11468 [MEDIUM] python3.14, python3.13, python3.12, python3.11, python3.10, python3.9,
python3.8, python3.7, python3.6, python3.5, python3.4 vulnerabilities
python3.14, python3.13, python3.12, python3.11, python3.10, python3.9,
python3.8, python3.7, python3.6, python3.5, python3.4 vulnerabilities
Denis Ledoux discovered that Python incorrectly parsed email message
headers. An attacker could possibly use this issue to inject arbitrary
headers into email messages. This issue only affected python3.6, python3.7,
python3.8, python3.9, python3.10, python3.11, python3.12, python3.13, and
python3.14 packages. (CVE-2025-11468)
Jacob Walls, Shai Berger, and Natalia Bidart discovered that Python
inefficiently parsed XML input with quadratic complexity. An attacker could
possibly use this issue to cause a denial of service. (CVE-2025-12084)
It was discovered that Python incorrectly parsed malicious plist files. An
attacker could possibly use this issue
GHSA
GHSA-39h2-3mq3-959g: When folding a long comment in an email header containing exclusively unfoldable characters, the parenthesis would not be preserved
ghsa_unreviewed·2026-01-21
CVE-2025-11468 [MEDIUM] CWE-93 GHSA-39h2-3mq3-959g: When folding a long comment in an email header containing exclusively unfoldable characters, the parenthesis would not be preserved
When folding a long comment in an email header containing exclusively unfoldable characters, the parenthesis would not be preserved. This could be used for injecting headers into email messages where addresses are user-controlled and not sanitized.
OSV
CVE-2025-11468: When folding a long comment in an email header containing exclusively unfoldable characters, the parenthesis would not be preserved
osv·2026-01-20·CVSS 5.7
CVE-2025-11468 [MEDIUM] CVE-2025-11468: When folding a long comment in an email header containing exclusively unfoldable characters, the parenthesis would not be preserved
When folding a long comment in an email header containing exclusively unfoldable characters, the parenthesis would not be preserved. This could be used for injecting headers into email messages where addresses are user-controlled and not sanitized.
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2025-11468 python3.9: Missing character filtering in Python [fedora-42]
bugzilla·2026-01-21·CVSS 5.7
CVE-2025-11468 [MEDIUM] CVE-2025-11468 python3.9: Missing character filtering in Python [fedora-42]
CVE-2025-11468 python3.9: Missing character filtering in Python [fedora-42]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Discussion:
We're not going to proactively fix this in EOL Pythons in Fedora to keep them as close as possible to their EL clones.
---
*** This bug has been marked as a duplicate of bug 2431836 ***
Bugzilla
CVE-2025-11468 asahi-installer: Missing character filtering in Python [fedora-42]
bugzilla·2026-01-21·CVSS 5.7
CVE-2025-11468 [MEDIUM] CVE-2025-11468 asahi-installer: Missing character filtering in Python [fedora-42]
CVE-2025-11468 asahi-installer: Missing character filtering in Python [fedora-42]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Discussion:
This message is a reminder that Fedora Linux 42 is nearing its end of life.
Fedora will stop maintaining and issuing updates for Fedora Linux 42 on 2026-05-13.
It is Fedora's policy to close all bug reports from releases that are no longer
maintained. At that time this bug will be closed as EOL if it remains open with a
'version' of '42'.
Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, change the 'ver
Bugzilla
CVE-2025-11468 python3.6: Missing character filtering in Python [fedora-42]
bugzilla·2026-01-21·CVSS 5.7
CVE-2025-11468 [MEDIUM] CVE-2025-11468 python3.6: Missing character filtering in Python [fedora-42]
CVE-2025-11468 python3.6: Missing character filtering in Python [fedora-42]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Discussion:
We're not going to proactively fix this in EOL Pythons in Fedora to keep them as close as possible to their EL clones.
---
This message is a reminder that Fedora Linux 42 is nearing its end of life.
Fedora will stop maintaining and issuing updates for Fedora Linux 42 on 2026-05-13.
It is Fedora's policy to close all bug reports from releases that are no longer
maintained. At that time this bug will be closed as EOL if it remains open with a
'version' of '42'.
Package Maintainer
Bugzilla
CVE-2025-11468 python3.9: Missing character filtering in Python [fedora-all]
bugzilla·2026-01-21·CVSS 5.7
CVE-2025-11468 [MEDIUM] CVE-2025-11468 python3.9: Missing character filtering in Python [fedora-all]
CVE-2025-11468 python3.9: Missing character filtering in Python [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Discussion:
We're not going to proactively fix this in EOL Pythons in Fedora to keep them as close as possible to their EL clones.
---
*** Bug 2431801 has been marked as a duplicate of this bug. ***
Bugzilla
CVE-2025-11468 cpython: Missing character filtering in Python
bugzilla·2026-01-20·CVSS 5.7
CVE-2025-11468 [MEDIUM] CVE-2025-11468 cpython: Missing character filtering in Python
CVE-2025-11468 cpython: Missing character filtering in Python
When folding a long comment in an email header containing exclusively unfoldable characters, the parenthesis would not be preserved. This could be used for injecting headers into email messages where addresses are user-controlled and not sanitized.
Wiz
CVE-2025-11468 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 5.7
CVE-2025-11468 [MEDIUM] CVE-2025-11468 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2025-11468 :
Python Interpreter vulnerability analysis and mitigation
When folding a long comment in an email header containing exclusively unfoldable characters, the parenthesis would not be preserved. This could be used for injecting headers into email messages where addresses are user-controlled and not sanitized.
Source : NVD
## 5.7
Score
Published January 20, 2026
Severity MEDIUM
CNA Score 5.7
Affected Technologies
Python Interpreter
Wolfi
Has Public Exploit No
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Percentile (EPSS) 11.6
Exploitation Probability (EPSS) N/A
Affected packages and libraries
python39-devel:3.9::python39-toml
python39-devel:3.9::python-idna
Sources
NVD
CBL-Mariner 3.0 Severity MEDIUM
https://github.com/python/cpython/commit/003b8315669b9f08b1010a49071f73f15f818094https://github.com/python/cpython/commit/17d1490aa97bd6b98a42b1a9b324ead84e7fd8a2https://github.com/python/cpython/commit/61614a5e5056e4f61ced65008d4576f3df34acb6https://github.com/python/cpython/commit/a76e4cd62dd68e7cbe86e37e6ed988495a646b66https://github.com/python/cpython/commit/e9970f077240c7c670e8a6fc6662f2b30d3b6ad0https://github.com/python/cpython/commit/f738386838021c762efea6c9802c82de65e87796https://github.com/python/cpython/issues/143935https://github.com/python/cpython/pull/143936https://mail.python.org/archives/list/[email protected]/thread/FELSEOLBI2QR6YLG6Q7VYF7FWSGQTKLI/
2026-01-20
Published