CVE-2001-1245: Opera 5.0 for Linux does not properly handle malformed HTTP headers, which allows remote attackers to cause a

This month

MEDIUM 5.0WATCHLISTDOWNGRADE

CVE-2001-1245 is a medium-severity flaw (CVSS 5.0) affecting opera web browser. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Opera 5.0 for Linux does not properly handle malformed HTTP headers, which allows remote attackers to cause a denial of service, possibly with a header whose value is the same as a MIME header name.

Why this priority

On your watchlist

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	2.4% (top 16%)
CISA exploited list	No
Published	2001-07-09
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: opera software

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2001-07-09 04:00 UTCPublished CVE record published
2026-06-16 21:55 UTCUpdated Record last modified

opera software opera web browser DOWNGRADE

Affected: 5.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 5.0

1. Check installed version

apt-cache policy opera-web-browser || rpm -q opera-web-browser || opera-web-browser --version

2. No fixed release: DOWNGRADE to a release before 5.0 (Debian / Ubuntu)

apt-cache madison opera-web-browser sudo apt install opera-web-browser=<VERSION_BEFORE_5.0> sudo apt-mark hold opera-web-browser

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list opera-web-browser sudo dnf downgrade opera-web-browser-<VERSION_BEFORE_5.0> sudo dnf versionlock add opera-web-browser

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2001-1245?

opera web browser: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2001-1245 being exploited?

CVE-2001-1245 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2001-1245 affect?

CVE-2001-1245 affects opera web browser. Severity is medium (CVSS 5.0). Opera 5.0 for Linux does not properly handle malformed HTTP headers, which allows remote attackers to cause a denial of service, possibly with a header whose value is the same as a MIME header name.

How urgent is CVE-2001-1245?

Priority 44/100. On your watchlist

Related CVEs

CVE-2005-0233 HIGH 7.5 DOWNGRADE DOWNGRADE The International Domain Name (IDN) support in Firefox 1.0, Camino .8.5, and Mozilla before 1.7.6 allows remot
CVE-2002-2358 MEDIUM 4.3 DOWNGRADE Cross-site scripting (XSS) vulnerability in the FTP view feature in Opera 6.0 and 6.01 through 6.04 allows rem
CVE-2002-2332 MEDIUM 5.0 DOWNGRADE Buffer overflow in Opera 6.01 allows remote attackers to cause a denial of service (crash) via an IMG tag with
CVE-2002-2311 MEDIUM 6.4 DOWNGRADE DOWNGRADE Microsoft Internet Explorer 6.0 and possibly others allows remote attackers to upload arbitrary file contents
CVE-2002-1091 HIGH 7.5 DOWNGRADE DOWNGRADE Netscape 6.2.3 and earlier, and Mozilla 1.0.1, allow remote attackers to corrupt heap memory and execute arbit

References

← Back to latest CVEs