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VulnerabilityPublished

CVE-2026-47265: aio-libs aiohttp · Origin Validation Error

Affects aio-libs aiohttpSource CVE Database V5

0

Not known to be exploited · CVSS 6.6 Medium : upgrade to 3.14.0 when convenient.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 4.0 base score
6.6Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 3.14.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 2 Jun 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade aio-libs aiohttp to 3.14.0.

Affected software

ProductAffectedFixed in
aio-libsaiohttpAffected
  • <3.14.0
Fixed in
  • 3.14.0
PyPIaiohttppkg:pypi/aiohttpOther threatsAffected
  • <3.14.0
Fixed in
  • 3.14.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade aiohttp to version 3.14.0 or later, where this issue is fixed. If upgrading is not possible, avoid using the `cookies` parameter on requests and instead set cookies via the `Cookie` header in the `headers` parameter, which is not vulnerable to this issue.

Description

### Summary Cookies set with the `cookies` parameter on requests are sent after following a cross-origin redirect. ### Impact If a developer uses the `cookies` parameter on a per-request basis then sensitive data might be leaked to an attacker if they manage to control a redirect. ### Workaround If unable to upgrade, using a `Cookie` header in the `headers` parameter is not vulnerable. ----- Patch: https://github.com/aio-libs/aiohttp/commit/f54c40851b0d6c4bbdab97ba518a223adda32478

References

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