CVE-2026-34520

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.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.46% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 38.0% of scored records. A rank, not a probability.

NVD base score

2.7 (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:L/VA:N/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 2026-06-17.

Red Hat severity

Low. 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.

Published

2026-04-01 20:27Z5 MO AGO

Last updated

2026-04-04 03:13Z5 MO AGO

Reserved

2026-03-30

Assigning CNA

GitHub_M

Record state

PUBLISHED

Severity

Low (CVSS 2.7)

CNA CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U

Weaknesses

• CWE-113Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')Variant
• CWE-1286Improper Validation of Syntactic Correctness of InputBase

Data version

5.2

Document digest

7bd7d363ff3c5665f05621257cf8a65e540b8ff92d453e94b91c8e8f2c3c8696

• github.comhttps://github.com/aio-libs/aiohttp/security/advisories/GHSA-63hf-3vf5-4wqfx_refsource_CONFIRM
• github.comhttps://github.com/aio-libs/aiohttp/commit/9370b9714a7a56003cacd31a9b4ae16eab109ba4x_refsource_MISC
• github.comhttps://github.com/aio-libs/aiohttp/releases/tag/v3.13.4x_refsource_MISC