CVE-2026-34516
AIOHTTP: Multipart Header Size Bypass
02 Description
AIOHTTP: Multipart Header Size Bypass
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.44% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 37.9% of scored records. A rank, not a probability.
- NVD base score
- 6.6 (CVSS v4.0), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/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
- NVD analysis status
- Analyzed. NVD last modified this record on 2026-10-26.
- Red Hat severity
- Moderate. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-04-01 20:13Z7 MO AGO
- Last updated
- 2026-04-04 03:11Z6 MO AGO
- Reserved
- 2026-03-30
- Assigning CNA
- GitHub_M
- Record state
- PUBLISHED
- Severity
- Medium (CVSS 6.6)
- CNA CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U
- Weaknesses
- CWE-770Allocation of Resources Without Limits or ThrottlingBase
- Data version
- 5.2
- Document digest
- 1e9ab49075710f64c8c527862e56a2cc95847c6b227869d83d81812547ba03af
05 Affected products
06 References
07 Fixed in
Debian 12
- python-aiohttp No fix yet
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- python-aiohttp No fix yet
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- python-aiohttp Fixed in 3.13.5-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 25.10
- python-aiohttp No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 26.10
- python-aiohttp No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 16.04 LTS
- python-aiohttp Fixed in 0.20.2-1ubuntu0.1~esm1Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 18.04 LTS
- python-aiohttp Fixed in 3.0.1-1ubuntu0.1~esm7Available with Ubuntu Pro: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 22.04 LTS
- python-aiohttp Fixed in 3.8.1-4ubuntu0.2+esm3Available with Ubuntu Pro: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 24.04 LTS
- python-aiohttp Fixed in 3.9.1-1ubuntu0.1+esm3Available with Ubuntu Pro: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 26.04 LTS
- python-aiohttp Fixed in 3.13.3-3ubuntu1+esm1Available with Ubuntu Pro: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.