When reading an HTTP response from a server, if no read amount is specified, the default behavior will be to use Content-Length. This allows a malicious server to cause the client to read large amounts of data into memory, potentially causing OOM or other DoS.
CVE-2025-13836
Score 9.1 from GitHub Security Advisory published 2025-12-01. NVD baseline CVSS 7.5; sources differ by 1.6.
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 9.1(medium)
- EPSS
- 71.7%
- KEV
- Not listed
Published
December 1, 2025
Last Modified
May 18, 2026
Advisory Details (9)
Auto-updated May 18, 2026Mailman 3 [CVE-2025-13836] Excessive read buffering DoS in http.client - Security-announce - python.org
https://mail.python.org/archives/list/[email protected]/thread/OQ6G7MKRQIS3OAREC3HNG3D2DPOU34XO/gh-119451: Fix a potential denial of service in http.client by serhiy-storchaka · Pull Request #119454 · python/cpython · GitHub
https://github.com/python/cpython/pull/119454Out-of-memory when reading a HTTP response with large Content-Length · Issue #119451 · python/cpython · GitHub
https://github.com/python/cpython/issues/119451[3.11] gh-119451: Fix a potential denial of service in http.client (G… · python/cpython@afc40bd · GitHub
https://github.com/python/cpython/commit/afc40bdd3dd71f343fd9016f6d8eebbacbd6587c[3.10] gh-119451: Fix a potential denial of service in http.client (G… · python/cpython@5dc1016 · GitHub
https://github.com/python/cpython/commit/5dc101675fd22918facbbe0fecdc821502beaaf0gh-119451: Fix a potential denial of service in http.client (GH-119454) · python/cpython@5a4c4a0 · GitHub
https://github.com/python/cpython/commit/5a4c4a033a4a54481be6870aa1896fad732555b5[3.14] gh-119451: Fix a potential denial of service in http.client (G… · python/cpython@4ce2790 · GitHub
https://github.com/python/cpython/commit/4ce27904b597c77d74dd93f2c912676021a99155[3.13] gh-119451: Fix a potential denial of service in http.client (G… · python/cpython@289f29b · GitHub
https://github.com/python/cpython/commit/289f29b0fe38baf2d7cb5854f4bb573cc34a6a15[3.12] gh-119451: Fix a potential denial of service in http.client (G… · python/cpython@14b1fdb · GitHub
https://github.com/python/cpython/commit/14b1fdb0a94b96f86fc7b86671ea9582b8676628Vendor Advisories for CVE-2025-13836(13)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2026:16174Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat AI Inference Server 3.3.3 (Spyre)
- RHSA-2026:8824Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
- RHSA-2026:8822Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
- RHSA-2026:8748Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat AI Inference Server Model Optimization Tools 3.3.1 (CUDA)
- RHSA-2026:8746Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat AI Inference Server 3.3.1 (CUDA)
- RHSA-2026:8747Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat AI Inference Server 3.3.1 (ROCm)
- RHSA-2026:7661Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
- RHSA-2026:7443Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
- +5 more
Patch Availability(24)
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Additional Vendor Advisories
(12)
Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.
- Microsoft MSRCCVE-2025-138362025-12-05
Excessive read buffering DoS in http.client
- Red HatRHSA-2026:1374MODERATE2025-12-01
RHSA-2026:1374 — Moderate
- Red HatRHSA-2026:1408MODERATE2025-12-01
RHSA-2026:1408 — Moderate
- Red HatRHSA-2026:1410MODERATE2025-12-01
RHSA-2026:1410 — Moderate
- Red HatRHSA-2026:1828MODERATE2025-12-01
RHSA-2026:1828 — Moderate
- Red HatRHSA-2026:1892MODERATE2025-12-01
RHSA-2026:1892 — Moderate
- Red HatRHSA-2026:1893MODERATE2025-12-01
RHSA-2026:1893 — Moderate
- Red HatRHSA-2026:1922MODERATE2025-12-01
RHSA-2026:1922 — Moderate
- Red HatRHSA-2026:2084MODERATE2025-12-01
RHSA-2026:2084 — Moderate
- Red HatRHSA-2026:2233MODERATE2025-12-01
RHSA-2026:2233 — Moderate
- Red HatRHSA-2026:2419MODERATE2025-12-01
RHSA-2026:2419 — Moderate
- UbuntuUSN-7951-1MEDIUM
Python vulnerability
Data Freshness Timeline
(refreshed 11× in last 7d / 44× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-12 05:46 UTCEPSS rescore
- 2026-07-12 05:45 UTCEPSS rescore
- 2026-07-11 08:26 UTCEPSS rescore
- 2026-07-11 08:26 UTCEPSS rescore
- 2026-07-10 01:15 UTCOSV refresh
- 2026-07-09 19:09 UTCEPSS rescore
- 2026-07-08 15:14 UTCEPSS rescore
- 2026-07-07 13:45 UTCEPSS rescore
- 2026-07-06 16:26 UTCEPSS rescore
- 2026-07-06 02:22 UTCEPSS rescore
- 2026-07-06 02:22 UTCEPSS rescore
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-04 06:30 UTCEPSS rescore
- 2026-07-01 15:06 UTCEPSS rescore
- 2026-06-30 23:21 UTCEPSS rescore
- 2026-06-29 14:06 UTCEPSS rescore
- 2026-06-28 14:07 UTCEPSS rescore
- 2026-06-28 14:07 UTCEPSS rescore
- 2026-06-28 04:55 UTCEPSS rescore
- 2026-06-27 03:08 UTCEPSS rescore
- 2026-06-27 03:08 UTCEPSS rescore
- 2026-06-25 13:49 UTCEPSS rescore
- 2026-06-25 13:49 UTCEPSS rescore
- 2026-06-24 14:04 UTCEPSS rescore
- 2026-06-24 14:04 UTCEPSS rescore
Show 74 moreShow fewer
- 2026-06-23 21:32 UTCEPSS rescore
- 2026-06-22 14:25 UTCEPSS rescore
- 2026-06-22 14:25 UTCEPSS rescore
- 2026-06-21 14:56 UTCEPSS rescore
- 2026-06-21 14:56 UTCEPSS rescore
- 2026-06-21 11:31 UTCOSV refresh
- 2026-06-21 01:59 UTCEPSS rescore
- 2026-06-21 01:59 UTCEPSS rescore
- 2026-06-19 19:25 UTCEPSS rescore
- 2026-06-19 19:25 UTCEPSS rescore
- 2026-06-18 17:52 UTCEPSS rescore
- 2026-06-18 17:52 UTCEPSS rescore
- 2026-06-17 17:52 UTCEPSS rescore
- 2026-06-16 17:52 UTCEPSS rescore
- 2026-06-15 17:48 UTCEPSS rescore
- 2026-06-14 23:17 UTCEPSS rescore
- 2026-06-13 22:59 UTCEPSS rescore
- 2026-06-13 22:59 UTCEPSS rescore
- 2026-06-12 23:11 UTCEPSS rescore
- 2026-06-11 13:59 UTCEPSS rescore
- 2026-06-10 22:18 UTCEPSS rescore
- 2026-06-10 13:21 UTCEPSS rescore
- 2026-06-08 14:16 UTCEPSS rescore
- 2026-06-08 14:16 UTCEPSS rescore
- 2026-06-07 15:24 UTCEPSS rescore
- 2026-06-06 13:47 UTCEPSS rescore
- 2026-06-06 13:47 UTCEPSS rescore
- 2026-06-05 22:46 UTCEPSS rescore
- 2026-06-05 22:46 UTCEPSS rescore
- 2026-06-05 06:10 UTCEPSS rescore
- 2026-06-05 06:10 UTCEPSS rescore
- 2026-06-04 13:11 UTCEPSS rescore
- 2026-06-04 13:11 UTCEPSS rescore
- 2026-06-02 20:12 UTCEPSS rescore
- 2026-06-02 20:12 UTCEPSS rescore
- 2026-06-02 03:39 UTCOSV refresh
- 2026-06-01 13:51 UTCEPSS rescore
- 2026-06-01 13:51 UTCEPSS rescore
- 2026-05-31 22:30 UTCEPSS rescore
- 2026-05-31 22:30 UTCEPSS rescore
- 2026-05-31 00:16 UTCEPSS rescore
- 2026-05-31 00:16 UTCEPSS rescore
- 2026-05-29 13:44 UTCEPSS rescore
- 2026-05-28 13:44 UTCEPSS rescore
- 2026-05-28 13:44 UTCEPSS rescore
- 2026-05-28 13:44 UTCEPSS rescore
- 2026-05-28 13:44 UTCEPSS rescore
- 2026-05-27 13:40 UTCEPSS rescore
- 2026-05-27 13:40 UTCEPSS rescore
- 2026-05-27 13:40 UTCEPSS rescore
- 2026-05-27 13:40 UTCEPSS rescore
- 2026-05-26 13:43 UTCEPSS rescore
- 2026-05-26 13:43 UTCEPSS rescore
- 2026-05-26 13:43 UTCEPSS rescore
- 2026-05-26 13:43 UTCEPSS rescore
- 2026-05-26 07:18 UTCEPSS rescore
- 2026-05-26 07:18 UTCEPSS rescore
- 2026-05-26 07:18 UTCEPSS rescore
- 2026-05-26 07:18 UTCEPSS rescore
- 2026-05-24 16:56 UTCEPSS rescore
- 2026-05-23 15:20 UTCEPSS rescore
- 2026-05-22 21:16 UTCEPSS rescore
- 2026-05-22 21:16 UTCEPSS rescore
- 2026-05-22 21:16 UTCEPSS rescore
- 2026-05-21 22:42 UTCEPSS rescore
- 2026-05-21 04:08 UTCEG score recompute
- 2026-05-21 04:08 UTCVendor advisory
- 2026-05-21 04:07 UTCGHSA enrichment
- 2026-05-20 11:21 UTCEPSS rescore
- 2026-05-20 11:21 UTCEPSS rescore
- 2026-05-20 11:21 UTCEPSS rescore
- 2026-05-20 11:21 UTCEPSS rescore
- 2026-05-20 11:21 UTCEPSS rescore
- 2026-05-18 21:30 UTCEPSS rescore
Related CVEs(same vendor + same CWE)
Same vendor
10 shownmsrc · redhat
Same CWE
10 shownCWE-400
Frequently asked(5)
What is CVE-2025-13836?
When was CVE-2025-13836 disclosed?
Is CVE-2025-13836 actively exploited?
What is the CVSS score of CVE-2025-13836?
How do I remediate CVE-2025-13836?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2025-13836
Is Your Infrastructure Affected by CVE-2025-13836?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.